CN115185136A - Double-optical-frequency comb generation device and method with adjustable repetition frequency - Google Patents

Double-optical-frequency comb generation device and method with adjustable repetition frequency Download PDF

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CN115185136A
CN115185136A CN202210667799.4A CN202210667799A CN115185136A CN 115185136 A CN115185136 A CN 115185136A CN 202210667799 A CN202210667799 A CN 202210667799A CN 115185136 A CN115185136 A CN 115185136A
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李晓洲
李博
周晓清
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Dalian University of Technology
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    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
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Abstract

A double-optical-frequency comb generating device with adjustable repetition frequency and a method thereof comprise an optical-frequency comb signal source, an optical coupler used for dividing an input optical-frequency comb into a first optical-frequency comb and a second optical-frequency comb, a first phase modulator, a second phase modulator, a third phase modulator, a fourth phase modulator, a first optical circulator, a second optical circulator, a frequency domain second-order phase modulation module and a single-mode optical fiber. The optical coupler is respectively connected with the first phase modulator and the second phase modulator through optical fibers; the frequency domain second-order phase modulation module applies frequency domain second-order phase modulation to the optical pulse signal; the third phase modulator applies time domain second order phase modulation III to the optical pulse signal; the fourth phase modulator applies time-domain second-order phase modulation four to the optical pulse signal. After the second-order dispersion parameter of the frequency domain second-order phase modulation module is determined, the first, second, third and fourth time domain second-order phase modulation are changed, so that the repetition frequencies of the first optical frequency comb output 1 and the second optical frequency comb output 2 can be flexibly adjusted. The invention has the advantages of simple structure, higher stability, good coherence and the like.

Description

Double-optical-frequency comb generation device and method with adjustable repetition frequency
Technical Field
The invention belongs to the technical field of optical frequency combs, and relates to a double-optical frequency comb generating device and method with adjustable repetition frequency.
Background
The dual optical frequency comb signal generation technology is widely applied to the fields of precision spectroscopy, dual optical frequency comb distance measurement, optical communication and the like by virtue of the advantages of high resolution, high sensitivity, good coherence and the like. The existing double-optical-frequency comb signal generation technology still has the problems of complex system structure, poor repetition frequency tunability and the like if two mode-locked lasers are subjected to phase locking or double-optical-frequency comb generation is realized based on a single resonant cavity. Ming Yan et al, published in the academic journal "Light: in an academic paper 'Mid-original dual-comb spectrum with electro-optical modulators' (infrared double-comb spectrometers in electro-optical modulators) in Science & Applications, a double-optical frequency comb generation method based on electro-optical modulation continuous waves is provided, which has better repetition frequency tunability but is limited by modulator bandwidth, the spectrum range of generated double-optical frequency comb signals is narrower, and operations such as optical amplification, nonlinear spectrum spreading and the like are required subsequently, so that the complexity of the system is increased.
Disclosure of Invention
The invention mainly aims at the problems of complex system structure, poor repetition frequency tunability and the like in the traditional double-optical-frequency comb signal generation technology, and provides a double-optical-frequency comb generation device and method with adjustable repetition frequency. The invention aims to provide a double-optical-frequency comb generating device and method with adjustable repetition frequency.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a double-optical-frequency comb generating device with adjustable repetition frequency comprises an optical-frequency comb signal source 1, an optical coupler 2, a first phase modulator 3, a second phase modulator 4, a first optical circulator 5, a second optical circulator 6, a frequency domain second-order phase modulation module 7, a third phase modulator 8, a fourth phase modulator 9 and a single-mode optical fiber 10 (comprising optical fiber links 10a and 10 b). The optical frequency comb signal source 1 can be any signal source capable of generating an optical frequency comb with a specific repetition frequency, and is used for generating an input optical frequency comb; the optical coupler 2 is used for dividing an input optical frequency comb into two parts according to any power distribution proportion, and is respectively used for generating a first optical frequency comb and a second optical frequency comb, and the optical coupler 2 is respectively connected with the first phase modulator 3 and the second phase modulator 4 through a single-mode optical fiber 10; the first phase modulator 3 is used for applying time domain second order phase modulation one to an input optical frequency comb; the second phase modulator 4 is used for applying time domain second-order phase modulation II to the input optical frequency comb; the first optical circulator 5 is used for connecting the first phase modulator 3, the frequency domain second-order phase modulation module 7 and the third phase modulator 8; the second optical circulator 6 is used for connecting the second phase modulator 4, the frequency domain second-order phase modulation module 7 and the fourth phase modulator 9; the frequency domain second-order phase modulation module 7 is used for applying frequency domain second-order phase modulation to the optical pulse signal output by the first optical circulator 5 and the optical pulse signal output by the second optical circulator 6 based on the second-order dispersion amount provided by the second-order dispersion medium; the third phase modulator 8 is configured to apply time-domain second-order phase modulation three to the optical pulse signal output by the first optical circulator 5; and the fourth phase modulator 9 is configured to apply second-order time-domain phase modulation four to the optical pulse signal output by the second optical circulator 6. Wherein: the first optical circulator 5 includes three ports of a first port 5a, a second port 5b and a third port 5c, the second optical circulator 6 includes three ports of a first port 6a, a second port 6b and a third port 6c, and the frequency domain second order phase modulation module 7 includes two ports of a first port 7a and a second port 7 b. The first optical circulator 5 has the following characteristics: the optical pulse signal after passing through the first phase modulator 3 is input into the first optical circulator 5 from the first port 5a and is output through the second port 5 b; the optical pulse signal after passing through the frequency domain second-order phase modulation module 7 is input into the first optical circulator 5 from the second port 5b and is output through the third port 5 c. The second optical circulator 6 has the following characteristics: the optical pulse signal after passing through the second phase modulator 4 is input into the second optical circulator 6 from the first port 6a and is output through the second port 6 b; the optical pulse signal after passing through the frequency domain second-order phase modulation module 7 is input into the second optical circulator 6 from the second port 6b and is output through the third port 6 c. The frequency domain second-order phase modulation module 7 has the following two working modes, namely a first working mode: an optical pulse signal is input into the frequency domain second-order phase modulation module 7 from the first port 7a (or the second port 7 b), and is output from the second port 7b (or the first port 7 a) after being subjected to frequency domain second-order phase modulation; a second working mode: the optical pulse signal is input to the frequency domain second-order phase modulation module 7 from the first port 7a (or the second port 7 b), subjected to frequency domain second-order phase modulation, and then output from the first port 7a (or the second port 7 b).
Further, for the first operating mode, the input optical frequency comb generated by the optical frequency comb signal source 1 is divided into two parts according to a certain power distribution proportion after passing through the optical coupler 2, and the two parts are divided into two paths for continuous transmission. The first path of optical pulse signal passes through the optical fiber link 10a, and the first phase modulator 3 modulates the first modulation waveform onto the phase thereof, so as to realize the first time domain second order phase modulation of the optical pulse signal. The optical pulse signal after the time domain second order phase modulation enters the first optical circulator 5 through the first port 5a, and after being output by the second port 5b, enters the frequency domain second order phase modulation module 7 through the first port 7a, and is output by the second port 7b, so that the frequency domain second order phase modulation of the optical pulse signal is realized. The optical pulse signal output by the second port 7b enters the second optical circulator 6 through the second port 6b, and after being output through the third port 6c, the fourth phase modulator 9 modulates the modulation waveform onto the phase thereof, so as to realize the time domain second order phase modulation on the optical pulse signal, and complete the first optical frequency comb output 1. Similarly, the second optical pulse signal branched by the optical coupler 2 passes through the optical fiber link 10b, and the second phase modulator 4 modulates the second modulation waveform onto the phase thereof, so as to implement the second time-domain second-order phase modulation on the optical pulse signal. The optical pulse signal after the second time domain second order phase modulation enters the second optical circulator 6 through the first port 6a, and after being output by the second port 6b, enters the frequency domain second order phase modulation module 7 through the second port 7b, and is output by the first port 7a, so that the frequency domain second order phase modulation of the optical pulse signal is realized. The optical pulse signal output by the first port 7a enters the first optical circulator 5 through the second port 5b, and after being output by the third port 5c, the third phase modulator 8 modulates the third modulation waveform to the phase thereof, so as to realize the time domain second order phase modulation of the optical pulse signal, and complete the second optical frequency comb output 2. The method is characterized in that after the second-order dispersion parameter of the frequency domain second-order phase modulation module 7 is determined, the repetition frequency of the first optical frequency comb output 1 and the second optical frequency comb output 2 can be flexibly adjusted by changing the time domain second-order phase modulation I, the time domain second-order phase modulation II, the time domain second-order phase modulation III and the time domain second-order phase modulation IV.
Further, for the second operating mode, the input optical frequency comb generated by the optical frequency comb signal source 1 is divided into two parts according to a certain power distribution proportion after passing through the optical coupler 2, and the two parts are divided into two paths for continuous transmission. The first path of optical pulse signal passes through the optical fiber link 10a, and the first phase modulator 3 modulates the first modulation waveform onto the phase thereof, so as to realize the first time domain second-order phase modulation of the optical pulse signal. The optical pulse signal after the time domain second order phase modulation enters the first optical circulator 5 through the first port 5a, and after being output by the second port 5b, enters the frequency domain second order phase modulation module 7 through the first port 7a, and is output by the first port 7a, so that the frequency domain second order phase modulation of the optical pulse signal is realized. The optical pulse signal output by the first port 7a enters the first optical circulator 5 through the second port 5b, and after being output by the third port 5c, the third phase modulator 8 modulates the modulation waveform three onto the phase thereof, so as to realize the time domain second order phase modulation three of the optical pulse signal and complete the second optical frequency comb output 2. Similarly, the second optical pulse signal split by the optical coupler 2 passes through the optical fiber link 10b, and the second phase modulator 4 modulates the second modulation waveform onto the phase thereof, so as to implement the second time-domain second-order phase modulation on the optical pulse signal. And the optical pulse signal after the second time domain second order phase modulation enters the second optical circulator 6 through the first port 6a, is output by the second port 6b, enters the frequency domain second order phase modulation module 7 through the second port 7b, and is output by the second port 7b, so that the second order phase modulation of the optical pulse signal in the frequency domain is realized. The optical pulse signal output by the second port 7b enters the second optical circulator 6 through the second port 6b, and after being output through the third port 6c, the fourth phase modulator 9 modulates the modulation waveform onto the phase thereof, so as to realize the time domain second order phase modulation on the optical pulse signal, and complete the first optical frequency comb output 1. The method is characterized in that after the second-order dispersion parameter of the frequency domain second-order phase modulation module 7 is determined, the repetition frequency of the first optical frequency comb output 1 and the second optical frequency comb output 2 can be flexibly adjusted by changing the first time domain second-order phase modulation, the second time domain second-order phase modulation, the third time domain second-order phase modulation and the fourth time domain second-order phase modulation.
According to the double-optical-frequency comb generating device with the adjustable repetition frequency, the invention also provides two double-optical-frequency comb generating methods with the adjustable repetition frequency based on the device.
The first method is based on any optical frequency comb signal source with fixed repetition frequency, realizes double optical frequency comb output with adjustable repetition frequency, and the repetition frequency of the output double optical frequency comb is the result of the repetition frequency of the optical frequency comb signal source after integral multiple frequency multiplication, and comprises the following steps:
(1) An input optical frequency comb is generated by an arbitrary optical frequency comb signal source 1, and the repetition frequency of the input optical frequency comb is f 0 Corresponding to a time domain optical pulse repetition period of T 0 ＝1/f 0 . The input optical frequency comb is divided into two parts according to a certain power distribution proportion by the optical coupler 2, and the two parts are respectively used for generating a first optical frequency comb and a second optical frequency comb.
(2) And applying a first time domain second order phase modulation and a second time domain second order phase modulation to the two paths of optical pulse signals branched by the optical coupler 2 by using the first phase modulator 3 and the second phase modulator 4 respectively. The first modulation waveform involved in the first time-domain second-order phase modulation is as follows:
Figure BDA0003693550900000031
wherein q is 1 Is a frequency multiplication regulation factor I, q 1 Is a positive integer, and n represents the nth pulse. The second modulation waveform involved in the second time domain second order phase modulation is as follows:
Figure BDA0003693550900000041
wherein q is 2 Is a frequency multiplication regulation factor of two, q 2 Is a positive integer, and n represents the nth pulse.
(3) The frequency domain second-order phase modulation module 7 is utilized to apply frequency domain second-order phase modulation with equal magnitude and same sign (or opposite sign) to the two paths of optical pulse signals which are subjected to the time domain second-order phase modulation I and the time domain second-order phase modulation II respectively, and the two paths of optical pulse signals share the same frequency domain second-order phase modulation module 7. The first working mode of the frequency domain second-order phase modulation module 7 can be realized by second-order dispersion media such as a dispersion compensation optical fiber module and the like; the second working mode can be realized by second-order dispersion medium such as linear chirped Bragg fiber grating. The second-order dispersion amount provided by the second-order dispersion medium is satisfied
Figure BDA0003693550900000042
Figure BDA0003693550900000043
Wherein f is 0 Is the input optical frequency comb repetition frequency.
According to different working modes of the frequency domain second-order phase modulation module 7, taking a dispersion compensation optical fiber module as an example, the dispersion compensation optical fiber module is provided with two ports, optical signals are input from any port and output from the other port, and are always subjected to second-order dispersion transmission with equal size and same sign, so that completely consistent frequency domain second-order phase modulation can be realized; taking the linear chirped bragg fiber grating as an example, the linear chirped bragg fiber grating also has two ports, the input and output ports of optical signals are kept consistent, and the optical signals input by different ports undergo second-order dispersion transmission with equal magnitude and opposite signs, so that frequency domain second-order phase modulation with opposite signs can be realized. The invention has the advantages that the second-order dispersion amount required by the frequency domain second-order phase modulation is independent of the first frequency multiplication regulating factor and the second frequency multiplication regulating factor, and after the second-order dispersion parameter provided by the frequency domain second-order phase modulation module 7 is determined, the flexible adjustment of the repetition frequencies of the first optical frequency comb and the second optical frequency comb can be realized only by regulating the first time domain second-order phase modulation, the second time domain second-order phase modulation, the third time domain second-order phase modulation and the fourth time domain second-order phase modulation.
(4) And a third phase modulator 8 and a fourth phase modulator 9 are used for respectively applying third time domain second order phase modulation and fourth time domain second order phase modulation to the two paths of optical pulse signals passing through the frequency domain second order phase modulation module 7.
For the first working mode, the optical pulse signal modulated by the first-order phase modulation of the time domain and the second-order phase modulation of the frequency domain is modulated by the second-order phase modulation of the time domain, and the fourth-order phase modulation of the time domain is realized by the fourth phase modulator 9, wherein the related modulation waveform is as follows:
Figure BDA0003693550900000044
the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain are performed on the optical pulse signals, the third phase modulator 8 is used for realizing the third second-order phase modulation of the time domain, and the related modulation waveform is as follows:
Figure BDA0003693550900000045
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003693550900000046
p 1 ＝q 1 +1，s 1 from p 1 And m 1 Obtained according to the following formula:
Figure BDA0003693550900000047
p 2 ＝q 2 +1，s 2 from p 2 And m 2 Obtained according to the following formula:
Figure BDA0003693550900000048
sigma and the second-order dispersion beta provided by the frequency domain second-order phase modulation module 7 2 The relationship of (1) is:
Figure BDA0003693550900000049
taking a dispersion compensation fiber module as an example, σ = -1.
For the second working mode, the time domain second order phase modulation three is realized by the third phase modulator 8 through the optical pulse signals of the time domain second order phase modulation I and the frequency domain second order phase modulation, and the related modulation waveform three is as follows:
Figure BDA0003693550900000051
the second-order phase modulation of the time domain is carried out on the second-order phase modulation optical pulse signals through the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain, the fourth-order phase modulation of the time domain is realized through a fourth phase modulator 9, and the related modulation waveform is as follows:
Figure BDA0003693550900000052
wherein the content of the first and second substances,
Figure BDA0003693550900000053
p 1 ＝q 1 +1，s 1 from p 1 And m 1 Obtained according to the following formula:
Figure BDA0003693550900000054
p 2 ＝q 2 +1，s 2 from p 2 And m 2 Obtained according to the following formula:
Figure BDA0003693550900000055
sigma and the second-order dispersion beta provided by the frequency domain second-order phase modulation module 7 2 The relationship of (1) is:
Figure BDA0003693550900000056
taking the linearly chirped bragg fiber grating as an example, the second-order dispersion β experienced by the optical signals input and output from different ports thereof is determined according to the second-order dispersion β 2 The symbol pair σ is assigned.
(5) Respectively outputting a first optical frequency comb and a second optical frequency comb after time domain second order phase modulation IV and time domain second order phase modulation III, wherein the repetition frequency of the first optical frequency comb and the second optical frequency comb is the repetition frequency f of the input optical frequency comb 0 The integral multiple frequency multiplication result of (f) is respectively rep1 ＝q 1 ·f 0 And f rep2 ＝q 2 ·f 0 . Under the condition of not changing the second-order dispersion parameter of the frequency domain second-order phase modulation module 7, the frequency multiplication regulation factor q related to the time domain second-order phase modulation in the steps (2) and (4) is adjusted 1 And a frequency doubling regulatory factor of two q 2 Therefore, the generation of the double-optical frequency comb with flexibly adjustable repetition frequency can be realized.
In addition, the invention also provides a second double-optical-frequency comb generating method with adjustable repetition frequency, which is realized based on the device, based on any optical-frequency comb signal source with fixed repetition frequency, the double-optical-frequency comb output with adjustable repetition frequency is realized, and the repetition frequency of the output double-optical-frequency comb is the result of the repetition frequency of the optical-frequency comb signal source after integral multiple frequency division, and the method comprises the following steps:
(1) An input optical frequency comb is generated by an arbitrary optical frequency comb signal source 1, and the repetition frequency of the input optical frequency comb is f 0 Corresponding to a time domain optical pulse repetition period of T 0 ＝1/f 0 . The input optical frequency comb is divided into two parts according to a certain power distribution proportion by the optical coupler 2, and the two parts are respectively used for generating a first optical frequency comb and a second optical frequency comb.
(2) And a first phase modulator 3 and a second phase modulator 4 are used for applying a first time domain second order phase modulation and a second time domain second order phase modulation to the two paths of optical pulse signals branched by the optical coupler 2 respectively. The first modulation waveform involved in the first time-domain second-order phase modulation is as follows:
Figure BDA0003693550900000057
wherein q' 1 Is a frequency division regulation factor of one, p' 1 Is a frequency division regulation factor of two, q' 1 、p′ 1 Are all positive integers, and n represents the nth pulse. The second modulation waveform involved in the second time domain second order phase modulation is as follows:
Figure BDA0003693550900000061
wherein q' 2 Is a frequency division regulation factor of three, p' 2 Is a frequency division regulation factor of four, q' 2 、p′ 2 Are all positive integers, and n represents the nth pulse.
(3) The frequency domain second-order phase modulation module 7 is utilized to apply frequency domain second-order phase modulation with equal magnitude and same sign (or opposite sign) to the two paths of optical pulse signals which are subjected to the time domain second-order phase modulation I and the time domain second-order phase modulation II respectively, and the two paths of optical pulse signals share the same frequency domain second-order phase modulation module 7. The first working mode of the frequency domain second-order phase modulation module 7 can be realized by second-order dispersion media such as a dispersion compensation optical fiber module and the like; the second working mode can be realized by second-order dispersion media such as linear chirped Bragg fiber grating and the like. The second-order dispersion amount provided by the second-order dispersion medium is satisfied
Figure BDA0003693550900000062
Figure BDA0003693550900000063
Wherein f is 0 Is an input optical frequency comb repetition frequency, v' 1 Is a frequency division regulation factor of five, u' 1 Is a frequency division regulation factor of six, v' 2 Is a frequency division regulation factor of seven, u' 2 Is a frequency division regulation factor of eight, v' 1 、u′ 1 、v′ 2 、u′ 2 Are all positive integers. r' 1 ＝q′ 1 /v′ 1 、r′ 2 ＝q′ 2 /v′ 2 A first frequency-dividing factor and a second frequency-dividing factor, respectively, of the input optical-frequency comb repetition frequency.
According to different working modes of the frequency domain second-order phase modulation module 7, taking a dispersion compensation optical fiber module as an example, the dispersion compensation optical fiber module is provided with two ports, optical signals are input from any port and output from the other port, and are always subjected to second-order dispersion transmission with equal size and same sign, so that completely consistent frequency domain second-order phase modulation can be realized; taking the linear chirped bragg fiber grating as an example, the linear chirped bragg fiber grating also has two ports, the input and output ports of optical signals are kept consistent, and the optical signals input by different ports undergo second-order dispersion transmission with equal magnitude and opposite signs, so that frequency domain second-order phase modulation with opposite signs can be realized. The method has the advantages that after the second-order dispersion parameter required by frequency domain second-order phase modulation is determined, the flexible adjustment of the output first optical frequency comb and second optical frequency comb repetition frequency can be realized only by regulating and controlling the first time domain second-order phase modulation, the second time domain second-order phase modulation, the third time domain second-order phase modulation and the fourth time domain second-order phase modulation.
(4) And a third phase modulator 8 and a fourth phase modulator 9 are used for respectively applying a third time domain second order phase modulation and a fourth time domain second order phase modulation to the two paths of optical pulse signals passing through the frequency domain second order phase modulation module 7.
For the first working mode, the time domain second order phase modulation four is realized by the fourth phase modulator 9 through the optical pulse signal of the time domain second order phase modulation first and the frequency domain second order phase modulation, and the related modulation waveform four is:
Figure BDA0003693550900000064
the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain are performed on the optical pulse signals, the third phase modulator 8 is used for realizing the third second-order phase modulation of the time domain, and the related modulation waveform is as follows:
Figure BDA0003693550900000065
wherein s' 1 Is a frequency division regulation factor nine of u' 1 And v' 1 Obtained according to the following formula:
Figure BDA0003693550900000066
s′ 2 is a frequency division regulation factor of ten, and is composed of u' 2 And v' 2 Obtained according to the following formula:
Figure BDA0003693550900000071
sigma and the second-order dispersion beta provided by the frequency domain second-order phase modulation module 7 2 The relationship of (1) is:
Figure BDA0003693550900000072
taking a dispersion compensation fiber module as an example, σ = -1.
For the second working mode, the time domain second order phase modulation is realized through the third phase modulator 8 by the optical pulse signal of the time domain second order phase modulation first order phase modulation and the frequency domain second order phase modulationPhase modulation III, the related modulation waveform III is as follows:
Figure BDA0003693550900000073
the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain are performed on the optical pulse signals, the fourth-order phase modulation of the time domain is realized through a fourth phase modulator 9, and the related modulation waveform is as follows:
Figure BDA0003693550900000074
wherein s' 1 Is a frequency division regulation factor of nine, and is composed of u' 1 And v' 1 Obtained according to the following formula:
Figure BDA0003693550900000075
s′ 2 is a frequency division regulation factor of ten and is composed of u' 2 And v' 2 Obtained according to the following formula:
Figure BDA0003693550900000076
sigma and the second-order phase modulation module of the frequency domain provide 7 second-order dispersion amount beta 2 The relationship of (1) is:
Figure BDA0003693550900000077
taking the linear chirped bragg fiber grating as an example, the second-order dispersion beta experienced by the optical signal input and output from different ports thereof is determined according to the optical signal 2 Assigns a value to sigma.
(5) Respectively outputting a first optical frequency comb and a second optical frequency comb after time domain second-order phase modulation IV and time domain second-order phase modulation III, wherein the repetition frequency of the first optical frequency comb and the second optical frequency comb is the repetition frequency f of the input optical frequency comb 0 The integer multiple frequency division results of f rep1 ＝f 0 /r′ 1 And f rep2 ＝f 0 /r′ 2 . Regulating frequency division regulation factors of q 'related to time domain and frequency domain second-order phase modulation in steps (2), (3) and (4)' 1 And a frequency division regulation factor of two' 1 And a frequency division regulation factor of three q' 2 And a frequency division regulation factor of four p' 2 And five v 'of frequency division regulation factor' 1 And a frequency division regulation factor of six u' 1 Frequency division regulation and control factorSeven v 'fruit' 2 And a frequency division regulation factor of eight u' 2 Nine s 'frequency division regulation factor' 1 And a frequency division regulation factor of ten's' 2 The double-optical-frequency comb generating device with the adjustable repetition frequency can be realized, and the output repetition frequency of the double-optical-frequency comb generating device is flexible and adjustable.
The invention has the beneficial effects that:
(1) The invention is based on an optical frequency comb signal source with fixed repetition frequency, and the optical frequency comb signal source is divided into two paths by an optical coupler to respectively perform time domain and frequency domain phase modulation processing, thereby realizing double optical frequency comb output. Therefore, the double-optical-frequency comb generating device is simple in structure, high in stability and low in cost.
(2) According to the double-optical-frequency comb generation device and method, second-order dispersion parameters required by frequency domain second-order phase modulation do not need to be changed, the output double-optical-frequency comb repetition frequency can be flexibly adjusted only through time domain second-order phase modulation waveform regulation, and the output first optical-frequency comb repetition frequency and the output second optical-frequency comb repetition frequency can be respectively and independently adjusted.
(3) The double-optical-frequency comb generation device and method only relate to time domain and frequency domain second-order phase modulation, only have inherent loss caused by transmission of optical pulse signals in optical fibers and components, have higher energy efficiency, and can keep the stability and broadband characteristics of input optical-frequency comb signals.
(4) According to the device and the method for generating the double optical frequency combs, the generated double optical frequency combs are from the same optical frequency comb signal source and are subjected to the same second-order dispersion medium transmission to realize frequency domain second-order phase modulation, and high coherence between the output double optical frequency combs can be ensured.
Therefore, the invention breaks through a plurality of bottleneck limitations of the traditional double-optical-frequency comb signal generation technology, can realize flexible and adjustable repetition frequency on the premise of not changing a second-order dispersion medium based on the optical-frequency comb signal source with fixed repetition frequency, and has the advantages of simple structure, high stability, good coherence and the like.
Drawings
Fig. 1 is a schematic structural diagram of a dual-optical-frequency comb generating device with adjustable repetition frequency according to the present invention.
Fig. 2 is a schematic structural diagram of a first specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention.
Fig. 3 is a simulation diagram of a dual optical-frequency comb generated by using MATLAB when a first specific dual optical-frequency comb generating apparatus with an adjustable repetition frequency is used to generate 100GHz and 105GHz dual optical-frequency combs according to an embodiment of the present invention. FIG. 3 (a) is a simulation generated using MATLAB for a first optical frequency comb with a repetition frequency of 100 GHz; fig. 3 (b) is a simulation generated by a second optical-frequency comb having a repetition frequency of 105GHz using MATLAB.
Fig. 4 is a simulation diagram of a modulation waveform of a first phase modulator generated by using MATLAB when a first specific apparatus for generating a dual-optical-frequency comb with an adjustable repetition frequency according to an embodiment of the present invention generates dual-optical-frequency combs with 100GHz and 105GHz.
Fig. 5 is a second simulation diagram of a modulation waveform of the second phase modulator generated by MATLAB when the first specific apparatus for generating a dual-optical-frequency comb with an adjustable repetition frequency provided by the present invention generates a 100GHz dual-optical-frequency comb and a 105GHz dual-optical-frequency comb.
Fig. 6 is a third simulation diagram of a modulation waveform of a third phase modulator generated by using MATLAB when a first specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention generates dual-optical-frequency combs at 100GHz and 105GHz.
Fig. 7 is a fourth simulation diagram of a modulation waveform of a fourth phase modulator generated by using MATLAB when a first specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention generates dual-optical-frequency combs at 100GHz and 105GHz.
Fig. 8 is a schematic structural diagram of a second specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention.
Fig. 9 is a simulation diagram of a dual optical-frequency comb generated by using MATLAB when a second specific dual optical-frequency comb generating apparatus with an adjustable repetition frequency is used to generate dual optical-frequency combs of 11.1GHz and 10GHz according to an embodiment of the present invention. FIG. 9 (a) is a simulation generated using MATLAB of a first optical frequency comb with a repetition frequency of 11.1 GHz; FIG. 9 (b) is a simulation generated using MATLAB for a second optical frequency comb with a repetition frequency of 10GHz.
Fig. 10 is a simulation diagram of a modulation waveform of the first phase modulator generated by using MATLAB when the second specific apparatus for generating a dual-optical-frequency comb with an adjustable repetition frequency according to the embodiment of the present invention generates dual-optical-frequency combs at 11.1GHz and 10GHz.
Fig. 11 is a second simulation diagram of a modulation waveform of the second phase modulator generated by using MATLAB when the second specific apparatus for generating a dual optical-frequency comb with an adjustable repetition frequency provided by the present invention generates dual optical-frequency combs of 11.1GHz and 10GHz.
Fig. 12 is a third simulation diagram of a modulation waveform of a third phase modulator generated by using MATLAB when a second specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention generates dual-optical-frequency combs at 11.1GHz and 10GHz.
Fig. 13 is a fourth simulation diagram of a modulation waveform of a fourth phase modulator generated by MATLAB when a second specific apparatus for generating a dual-optical-frequency comb with an adjustable repetition frequency according to an embodiment of the present invention generates dual-optical-frequency combs at 11.1GHz and 10GHz.
In the figure: the optical fiber grating phase-shift compensation system comprises an optical frequency comb signal source 1, an optical coupler 2, a first phase modulator 3, a second phase modulator 4, a first optical circulator 5, a second optical circulator 6, a second phase modulator 7, a frequency domain second-order phase modulation module 8, a third phase modulator 9, a fourth phase modulator 9, a single-mode optical fiber 10 (comprising optical fiber links 10a and 10 b), a first adjustable optical delay line 11, a second adjustable optical delay line 12, a third adjustable optical delay line 13, a fourth adjustable optical delay line 14, a dispersion compensation optical fiber module 15 and a linear chirped Bragg optical fiber grating 16. 5a first port of a first optical circulator, 5b a second port of the first optical circulator, 5c a third port of the first optical circulator; 6a first port of a second optical circulator, 6b a second port of the second optical circulator, 6c a third port of the second optical circulator; a first port of the 7a frequency domain second-order phase modulation module, and a second port of the 7b frequency domain second-order phase modulation module; 15a first port of a dispersion compensating fiber optic module, 15b a second port of a dispersion compensating fiber optic module; 16a first port of the linearly chirped fiber bragg grating and 16b a second port of the linearly chirped fiber bragg grating.
Detailed Description
The following detailed description of the embodiments of the invention refers to the accompanying drawings.
Fig. 1 is a schematic structural diagram of the present invention, and as shown in the figure, the present invention provides a dual optical frequency comb generating apparatus with adjustable repetition frequency, which includes an optical frequency comb signal source 1, an optical coupler 2, a first phase modulator 3, a second phase modulator 4, a first optical circulator 5, a second optical circulator 6, a frequency domain second-order phase modulation module 7, a third phase modulator 8, and a fourth phase modulator 9, where the above components are formed by connecting single-mode optical fibers 10 (including optical fiber links 10a and 10 b) in series to form a communicated optical path.
The optical components have the following functions in the invention: the optical frequency comb signal source 1 is used for generating a repetition frequency f 0 The input optical frequency comb of (1); the optical coupler 2 is used for dividing the input optical frequency comb into two parts according to any power distribution proportion, and the two parts are respectively used for generating a first optical frequency comb and a second optical frequency comb; the first phase modulator 3 is used for applying time domain second-order phase modulation I to an input optical frequency comb; the second phase modulator 4 is used for applying time domain second-order phase modulation II to the input optical frequency comb; the first optical circulator 5 is used for connecting the first phase modulator 3, the frequency domain second-order phase modulation module 7 and the third phase modulator 8; the second optical circulator 6 is used for connecting the second phase modulator 4, the frequency domain second-order phase modulation module 7 and the fourth phase modulator 9; the frequency domain second-order phase modulation module 7 is used for applying frequency domain second-order phase modulation to the optical pulse signal output by the first optical circulator 5 and the optical pulse signal output by the second optical circulator 6 based on the second-order dispersion amount provided by the second-order dispersion medium; the third phase modulator 8 is configured to apply time-domain second-order phase modulation three to the optical pulse signal output by the first optical circulator 5; and the fourth phase modulator 9 is used for applying time domain second-order phase modulation four to the optical pulse signal output by the second optical circulator 6.
Fig. 2 is a schematic structural diagram of a first specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention. As shown in fig. 2, the optical frequency comb signal source comprises an optical frequency comb signal source 1, an optical coupler 2, a first optical frequency comb signal sourceThe phase modulator 3, the second phase modulator 4, the first optical circulator 5, the second optical circulator 6, the third phase modulator 8 and the fourth phase modulator 9, the first adjustable optical delay line 11, the second adjustable optical delay line 12, the third adjustable optical delay line 13, the fourth adjustable optical delay line 14 and the dispersion compensation optical fiber module 15, wherein the components are formed by serially connecting optical single-mode fibers 10 (including optical fiber links 10a and 10 b) to form a communicated optical path. Wherein, the optical frequency comb signal source 1 can generate fixed repetition frequency f 0 The input optical frequency comb of (1); the optical coupler 2 is an optical coupler having a coupling ratio of 50: 50. The first adjustable light delay line 11, the second adjustable light delay line 12, the third adjustable light delay line 13 and the fourth adjustable light delay line 14 are respectively used for enabling the optical pulse signal to correspond to a modulation waveform I of the first phase modulator 3, a modulation waveform II of the second phase modulator 4, a modulation waveform III of the third phase modulator 8 and a modulation waveform IV of the fourth phase modulator 9; the dispersion compensation fiber module 15 includes two ports, i.e., a first port 15a and a second port 15b, and an optical signal is input from any one port and output from the other port, and always undergoes second-order dispersion transmission with equal size and same sign, so that completely consistent frequency domain second-order phase modulation can be realized. Second order dispersion amount beta thereof 2 With input optical frequency comb repetition frequency f 0 Satisfies the following formula:
Figure BDA0003693550900000101
the first modulation waveform of the first phase modulator 3 is:
Figure BDA0003693550900000102
wherein q is 1 For the frequency doubling regulation factor one, n represents the nth pulse. The second modulation waveform of the second phase modulator 4 is:
Figure BDA0003693550900000103
wherein q is 2 For the second frequency multiplication regulation factor, n represents the nth pulse. The third modulation waveform of the third phase modulator 8 is:
Figure BDA0003693550900000104
wherein
Figure BDA0003693550900000105
p 2 ＝q 2 +1，s 2 From p 2 And m 2 Obtained according to the following formula:
Figure BDA0003693550900000106
the modulation waveform of the fourth phase modulator 9 is:
Figure BDA0003693550900000107
wherein
Figure BDA0003693550900000108
p 1 ＝q 1 +1，s 1 From p 1 And m 1 Obtained according to the following formula:
Figure BDA0003693550900000109
fig. 3 is a diagram showing simulation results generated by MATLAB according to a first specific embodiment of the apparatus for generating a dual optical-frequency comb with adjustable repetition frequency provided by the present invention. In this embodiment, the input optical frequency comb repetition frequency provided by the optical frequency comb signal source 1 is: f. of 0 =5GHz, the repetition frequencies of the output dual-optical-frequency combs are respectively f rep1 =100GHz and f rep2 =105GHz. The second-order dispersion amount of the dispersion compensation optical fiber module is as follows:
Figure BDA00036935509000001010
(D = -4991.3 ps/nm). The first modulation waveform of the first phase modulator is:
Figure BDA00036935509000001011
wherein q is 1 =20; the second modulation waveform of the second phase modulator is:
Figure BDA00036935509000001012
wherein q is 2 =21; the third modulation waveform of the third phase modulator is:
Figure BDA00036935509000001013
Figure BDA0003693550900000111
wherein s is 2 ＝13042，
Figure BDA0003693550900000119
The modulation waveform of the fourth phase modulator is:
Figure BDA0003693550900000112
wherein s is 1 ＝862，
Figure BDA0003693550900000113
The first, second, third and fourth modulation waveforms of the first, second, third and fourth phase modulators are shown in fig. 4, 5, 6 and 7, respectively.
Fig. 8 is a schematic structural diagram of a second specific dual-optical-frequency comb generating apparatus with an adjustable repetition frequency according to an embodiment of the present invention. As shown in fig. 8, the optical frequency comb signal source includes an optical frequency comb signal source 1, an optical coupler 2, a first phase modulator 3, a second phase modulator 4, a first optical circulator 5, a second optical circulator 6, a third phase modulator 8, and a fourth phase modulator 9, a first tunable optical delay line 11, a second tunable optical delay line 12, a third tunable optical delay line 13, a fourth tunable optical delay line 14, and a linear chirped bragg fiber grating 16, where the optical frequency comb signal source is formed by serially connecting optical single-mode fibers 10 (including fiber links 10a and 10 b) to form a communicated optical path. Wherein, the optical frequency comb signal source 1 can generate fixed repetition frequency f 0 The input optical frequency comb of (1); the optical coupler 2 is an optical coupler having a coupling ratio of 40: 60. A first adjustable light delay line 11, a second adjustable light delay line 12, a third adjustable light delay line 13 and a fourth adjustable light delay line 14 are respectively used for corresponding the light pulse signal to a modulation waveform I of the first phase modulator 3, a modulation waveform II of the second phase modulator 4, a modulation waveform III of the third phase modulator 8 and a modulation waveform IV of the fourth phase modulator 9; the chirped fiber Bragg grating 16 comprises a first port 16a and a second port 16b, and an optical signal is input from the 16a port, output from the 16a port or output from the 16b portThe second-order dispersion experienced by the port input and the port output of the 16b is equal in size and opposite in sign, and frequency-domain second-order phase modulation with equal size and opposite sign can be achieved. Second order dispersion amount beta thereof 2 With input optical frequency comb repetition frequency f 0 Satisfies the following formula:
Figure BDA0003693550900000114
Figure BDA0003693550900000115
wherein q' 1 Is a frequency division regulation factor of one, p' 1 Is a frequency division regulation factor of two, q' 2 Is a frequency division regulation factor of three, p' 2 Is a frequency division regulation factor of four, v' 1 Is a frequency division regulation factor of five, u' 1 Is a frequency division regulation factor of six, v' 2 Is a frequency division regulation factor of seven, u' 2 Is a frequency division regulation factor of eight, v' 1 、u′ 1 、v′ 2 、u′ 2 Are all positive integers. r' 1 ＝q′ 1 /v′ 1 、r′ 2 ＝q′ 2 /v′ 2 A first frequency-dividing factor and a second frequency-dividing factor, respectively, of the input optical-frequency comb repetition frequency. The first modulation waveform of the first phase modulator 3 is:
Figure BDA0003693550900000116
the second modulation waveform of the second phase modulator 4 is:
Figure BDA0003693550900000117
the third modulation waveform of the third phase modulator 8 is:
Figure BDA0003693550900000118
wherein s' 1 Is a frequency division regulation factor of nine, and is composed of u' 1 And v' 1 Obtained according to the following formula:
Figure BDA0003693550900000121
the modulation waveform of the fourth phase modulator 9 is:
Figure BDA0003693550900000122
Figure BDA0003693550900000123
wherein s' 2 Is a frequency division regulation factor of ten, and is composed of u' 2 And v' 2 Obtained according to the following formula:
Figure BDA0003693550900000124
fig. 9 is a diagram showing simulation results generated by MATLAB according to a second specific embodiment of the apparatus for generating a dual optical-frequency comb with adjustable repetition frequency provided by the present invention. In this embodiment, the input optical frequency comb repetition frequency provided by the optical frequency comb signal source 1 is: f. of 0 =100GHz, the repetition frequencies of the output dual-optical-frequency combs are respectively f rep1 =11.1GHz and f rep2 =10GHz. When the optical signal is input from the first port 16a and output from the first port 16a, the second-order dispersion amount experienced by the optical signal is:
Figure BDA0003693550900000125
Figure BDA0003693550900000126
(D = -31445.5 ps/nm); when the optical signal is input from the second port 16b and output from the second port 16b, the second-order dispersion amount experienced by the optical signal is:
Figure BDA0003693550900000127
Figure BDA0003693550900000128
(D =31445.5 ps/nm). The first modulation waveform of the first phase modulator is:
Figure BDA0003693550900000129
wherein q' 1 ＝63，p′ 1 =5; the second modulation waveform of the second phase modulator is:
Figure BDA00036935509000001210
wherein q' 2 ＝280，p′ 2 =1; the third modulation waveform of the third phase modulator is:
Figure BDA00036935509000001211
wherein s' 1 ＝10，v′ 1 =7; the modulation waveform of the fourth phase modulator is:
Figure BDA00036935509000001212
wherein s' 2 ＝1，v′ 2 =28. The first, second, third and fourth modulation waveforms of the first, second, third and fourth phase modulators are shown in fig. 10, fig. 11, fig. 12 and fig. 13, respectively.
The above-mentioned embodiments only express the embodiments of the present invention, but not should be understood as the limitation of the scope of the invention patent, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.

Claims (6)

1. A double-optical-frequency comb generation device with adjustable repetition frequency is characterized by comprising an optical-frequency comb signal source (1), an optical coupler (2), a first phase modulator (3), a second phase modulator (4), a first optical circulator (5), a second optical circulator (6), a frequency domain second-order phase modulation module (7), a third phase modulator (8), a fourth phase modulator (9) and a single-mode optical fiber (10), wherein the single-mode optical fiber (10) comprises optical fiber links (10 a) and (10 b); the optical frequency comb signal source (1) is a signal source capable of generating an optical frequency comb with a specific repetition frequency, and is used for generating an input optical frequency comb; the optical coupler (2) is used for dividing an input optical frequency comb into two parts according to any power distribution proportion and is respectively used for generating a first optical frequency comb and a second optical frequency comb, and the optical coupler (2) is respectively connected with a first phase modulator (3) and a second phase modulator (4) through a single-mode optical fiber (10); the first phase modulator (3) is used for applying time domain second order phase modulation I to the input optical frequency comb; the second phase modulator (4) is used for applying time domain second-order phase modulation II to the input optical frequency comb; the first optical circulator (5) is used for connecting the first phase modulator (3), the frequency domain second-order phase modulation module (7) and the third phase modulator (8); the second optical circulator (6) is used for connecting the second phase modulator (4), the frequency domain second-order phase modulation module (7) and the fourth phase modulator (9); the frequency domain second-order phase modulation module (7) is used for applying frequency domain second-order phase modulation to the optical pulse signal output by the first optical circulator (5) and the optical pulse signal output by the second optical circulator (6) based on the second-order dispersion amount provided by the second-order dispersion medium; the third phase modulator (8) is used for applying time domain second-order phase modulation III to the optical pulse signal output by the first optical circulator (5); the fourth phase modulator (9) is used for applying time domain second-order phase modulation IV to the optical pulse signal output by the second optical circulator (6);
the first optical circulator (5) comprises a first port (5 a), a second port (5 b) and a third port (5 c), the second optical circulator (6) comprises a first port (6 a), a second port (6 b) and a third port (6 c), and the frequency domain second-order phase modulation module (7) comprises a first port (7 a) and a second port (7 b); the first optical circulator (5) has the characteristics that: the optical pulse signal after passing through the first phase modulator (3) is input into a first optical circulator (5) from a first port (5 a) and output through a second port (5 b); the optical pulse signal after passing through the frequency domain second-order phase modulation module (7) is input into the first optical circulator (5) from the second port (5 b) and is output through the third port (5 c); the second optical circulator (6) has the characteristics that: the optical pulse signal after passing through the second phase modulator (4) is input into the second optical circulator (6) from the first port (6 a) and output through the second port (6 b); the optical pulse signal after passing through the frequency domain second-order phase modulation module (7) is input into the second optical circulator (6) from the second port (6 b) and is output through the third port (6 c);
the frequency domain second-order phase modulation module (7) has the following two working modes, namely a first working mode: an optical pulse signal is input into the frequency domain second-order phase modulation module (7) from the first port (7 a) or the second port (7 b), and is output from the second port (7 b) or the first port (7 a) after being subjected to frequency domain second-order phase modulation; a second operating mode: the optical pulse signal is input into the frequency domain second-order phase modulation module (7) from the first port (7 a) or the second port (7 b), and is output from the first port (7 a) or the second port (7 b) after being subjected to frequency domain second-order phase modulation.
2. The apparatus according to claim 1, wherein for the first operating mode, the input optical-frequency comb generated by the optical-frequency comb signal source (1) is divided into two paths for further transmission after passing through the optical coupler (2); the first path of optical pulse signal passes through an optical fiber link (10 a), and a first phase modulator (3) modulates a modulation waveform I to the phase of the first path of optical pulse signal, so that time domain second-order phase modulation I of the optical pulse signal is realized; the optical pulse signal after the first time domain second-order phase modulation enters the first optical circulator (5) through the first port (5 a), is output by the second port (5 b), enters the frequency domain second-order phase modulation module (7) through the first port (7 a), and is output by the second port (7 b), so that the frequency domain second-order phase modulation of the optical pulse signal is realized; the optical pulse signal output by the second port (7 b) enters the second optical circulator (6) through the second port (6 b), and after the optical pulse signal is output through the third port (6 c), the fourth phase modulator (9) modulates the modulation waveform onto the phase of the optical pulse signal, so that the fourth time-domain second-order phase modulation of the optical pulse signal is realized, and the first optical frequency comb output 1 is completed; similarly, the second optical pulse signal branched by the optical coupler (2) passes through the optical fiber link (10 b), and the second phase modulator (4) modulates the second modulation waveform to the phase thereof, so as to realize the second time-domain second-order phase modulation of the optical pulse signal; the optical pulse signal after the second time domain second order phase modulation enters the second optical circulator (6) through the first port (6 a), and after being output by the second port (6 b), the optical pulse signal enters the frequency domain second order phase modulation module (7) through the second port (7 b) and is output by the first port (7 a), so that the frequency domain second order phase modulation of the optical pulse signal is realized; and the optical pulse signal output by the first port (7 a) enters the first optical circulator (5) through the second port (5 b), and after the optical pulse signal is output through the third port (5 c), the third phase modulator (8) modulates the modulation waveform three to the phase thereof, so that the time domain second order phase modulation of the optical pulse signal is realized, and the second optical frequency comb output 2 is completed.
3. The apparatus for generating a dual optical-frequency comb with adjustable repetition frequency as claimed in claim 1, wherein for the second operating mode, the input optical-frequency comb generated by the optical-frequency comb signal source (1) is divided into two paths for further transmission after passing through the optical coupler (2); the first path of optical pulse signal passes through an optical fiber link (10 a), and a first phase modulator (3) modulates a modulation waveform I to the phase of the first path of optical pulse signal, so that time domain second-order phase modulation I of the optical pulse signal is realized; the optical pulse signal after the first time domain second order phase modulation enters the first optical circulator (5) through the first port (5 a), and after being output by the second port (5 b), the optical pulse signal enters the frequency domain second order phase modulation module (7) through the first port (7 a), and is output by the first port (7 a), so that the frequency domain second order phase modulation of the optical pulse signal is realized; the optical pulse signal output by the first port (7 a) enters the first optical circulator (5) through the second port (5 b), and after the optical pulse signal is output through the third port (5 c), the third phase modulator (8) modulates the modulation waveform three to the phase thereof, so that the time domain second order phase modulation of the optical pulse signal is realized, and the second optical frequency comb output 2 is completed; similarly, the second optical pulse signal split by the optical coupler (2) passes through an optical fiber link (10 b), and the second phase modulator (4) modulates the second modulation waveform onto the phase thereof, so as to realize the second time-domain second-order phase modulation on the optical pulse signal; the optical pulse signal after the second time domain second order phase modulation enters the second optical circulator (6) through the first port (6 a), and after being output by the second port (6 b), the optical pulse signal enters the frequency domain second order phase modulation module (7) through the second port (7 b) and is output by the second port (7 b), so that the frequency domain second order phase modulation of the optical pulse signal is realized; the optical pulse signal output by the second port (7 b) enters the second optical circulator (6) through the second port (6 b), and after the optical pulse signal is output through the third port (6 c), the fourth phase modulator (9) modulates the modulation waveform onto the phase of the optical pulse signal, so that the time domain second-order phase modulation on the optical pulse signal is realized, and the first optical frequency comb output 1 is completed; after the second-order dispersion parameter of the frequency domain second-order phase modulation module (7) is determined, the repetition frequency of the first optical frequency comb output 1 and the second optical frequency comb output 2 can be flexibly adjusted by changing the first time domain second-order phase modulation, the second time domain second-order phase modulation, the third time domain second-order phase modulation and the fourth time domain second-order phase modulation.
4. The dual optical frequency comb generation device with adjustable repetition frequency according to any one of claims 1 to 3, wherein after the second-order dispersion parameter of the frequency domain second-order phase modulation module (7) is determined, the first time domain second-order phase modulation, the second time domain second-order phase modulation, the third time domain second-order phase modulation and the fourth time domain second-order phase modulation are changed, so that the repetition frequency of the first optical frequency comb output 1 and the second optical frequency comb output 2 can be flexibly adjusted.
5. A method for generating a double optical frequency comb with adjustable repetition frequency, which is realized based on the device of any one of claims 1 to 4, is characterized in that based on any optical frequency comb signal source with fixed repetition frequency, the output of the double optical frequency comb with adjustable repetition frequency is realized, and the repetition frequency of the output double optical frequency comb is the result of the repetition frequency of the optical frequency comb signal source after integral multiple frequency multiplication, and comprises the following steps:
(1) An input optical frequency comb is generated by an arbitrary optical frequency comb signal source (1) and has a repetition frequency f 0 Corresponding to a time domain optical pulse repetition period of T 0 ＝1/f 0 (ii) a An input optical frequency comb is divided into two parts through an optical coupler (2), and the two parts are respectively used for generating a first optical frequency comb and a second optical frequency comb;
(2) A first phase modulator (3) and a second phase modulator (4) are used for respectively applying a first time domain second order phase modulation and a second time domain second order phase modulation to two paths of optical pulse signals divided by the optical coupler (2); the first modulation waveform involved in the first time-domain second-order phase modulation is as follows:
Figure FDA0003693550890000031
wherein q is 1 Is a frequency multiplication regulation factor I, q 1 Is a positive integer, n represents the nth pulse; modulation of second order phase modulation in time domainThe second waveform is:
Figure FDA0003693550890000032
wherein q is 2 Is a frequency multiplication regulation factor of two, q 2 Is a positive integer, n represents the nth pulse;
(3) Frequency domain second-order phase modulation with equal magnitude, same sign or opposite sign is respectively applied to the two paths of optical pulse signals which are subjected to time domain second-order phase modulation I and time domain second-order phase modulation II by using a frequency domain second-order phase modulation module (7), and the two paths of optical pulse signals share the same frequency domain second-order phase modulation module (7); the first working mode of the frequency domain second-order phase modulation module (7) is realized by a dispersion compensation optical fiber module or other second-order dispersion media; the second working mode is realized by a linear chirp Bragg fiber grating or other second-order dispersion media; the second-order dispersion amount provided by the second-order dispersion medium is satisfied
Figure FDA0003693550890000033
Figure FDA0003693550890000034
Wherein f is 0 Is the input optical frequency comb repetition frequency;
(4) A third phase modulator (8) and a fourth phase modulator (9) are used for respectively applying a third time domain second order phase modulation and a fourth time domain second order phase modulation to the two paths of optical pulse signals passing through the frequency domain second order phase modulation module (7);
for the first working mode, the optical pulse signals modulated by the first time domain second-order phase modulation and the frequency domain second-order phase modulation are subjected to fourth time domain second-order phase modulation by a fourth phase modulator (9), and the related modulation waveform is as follows:
Figure FDA0003693550890000035
the second-order phase modulation of the time domain is carried out on the second-order phase modulation optical pulse signals through the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain, the third-order phase modulation of the time domain is realized through a third phase modulator (8), and the related modulation waveform is as follows:
Figure FDA0003693550890000036
wherein the content of the first and second substances,
Figure FDA0003693550890000037
p 1 ＝q 1 +1，s 1 from p 1 And m 1 Obtained according to the following formula:
Figure FDA0003693550890000038
p 2 ＝q 2 +1，s 2 from p 2 And m 2 Obtained according to the following formula:
Figure FDA0003693550890000041
sigma and a second-order dispersion amount beta provided by the frequency domain second-order phase modulation module (7) 2 The relationship of (1) is:
Figure FDA0003693550890000042
for the second mode of operation, it is necessary to interchange the phase modulation waveform three and the phase modulation waveform four, while depending on the second-order dispersion β experienced 2 Assigning a value to sigma;
(5) Respectively outputting a first optical frequency comb and a second optical frequency comb after time domain second-order phase modulation IV and time domain second-order phase modulation III, wherein the repetition frequency of the first optical frequency comb and the second optical frequency comb is the repetition frequency f of the input optical frequency comb 0 The integer multiple of frequency result of (f) is respectively rep1 ＝q 1 ·f 0 And f rep2 ＝q 2 ·f 0 (ii) a Under the condition of not changing the second-order dispersion parameter of the frequency domain second-order phase modulation module (7), adjusting the frequency multiplication regulation factor q involved in the time domain second-order phase modulation in the steps (2) and (4) 1 And frequency multiplication regulatory factor iq 2 Therefore, the generation of the double-optical frequency comb with flexibly adjustable repetition frequency can be realized.
6. A method for generating a double optical-frequency comb with adjustable repetition frequency, which is realized based on the device of any one of claims 1 to 4, wherein the method is characterized in that based on any optical-frequency comb signal source with fixed repetition frequency, the output of the double optical-frequency comb with adjustable repetition frequency is realized, and the repetition frequency of the output double optical-frequency comb is the result of the repetition frequency of the optical-frequency comb signal source after being divided by integer times, and comprises the following steps:
(1) An input optical frequency comb is generated by an arbitrary optical frequency comb signal source (1) and has a repetition frequency f 0 Corresponding to a time domain optical pulse repetition period of T 0 ＝1/f 0 (ii) a An optical coupler (2) divides an input optical frequency comb into two parts according to a certain power distribution proportion, and the two parts are respectively used for generating a first optical frequency comb and a second optical frequency comb;
(2) A first phase modulator (3) and a second phase modulator (4) are used for respectively applying a first time domain second order phase modulation and a second time domain second order phase modulation to two paths of optical pulse signals divided by the optical coupler (2); the first modulation waveform involved in the first time-domain second-order phase modulation is as follows:
Figure FDA0003693550890000043
wherein q' 1 Is a frequency division regulation factor of one, p' 1 Is a frequency division regulation factor of two, q' 1 、p′ 1 Are all positive integers, and n represents the nth pulse; the second modulation waveform involved in the second time domain second order phase modulation is as follows:
Figure FDA0003693550890000044
wherein q' 2 Is a frequency division regulation factor of three, p' 2 Is a frequency division regulation factor of four, q' 2 、p′ 2 Are all positive integers, and n represents the nth pulse;
(3) Frequency domain second-order phase modulation modules (7) are utilized to respectively apply equal-magnitude, same-sign or opposite-magnitude frequency domain second-order phase modulation to the two paths of optical pulse signals subjected to the time domain second-order phase modulation I and the time domain second-order phase modulation II, and the two paths of optical pulse signals share the same frequency domain second-order phase modulation module (7); the first working mode of the frequency domain second-order phase modulation module (7) is realized by a dispersion compensation optical fiber module or other second-order dispersion media; the second operating mode being a chirped fiber Bragg grating or otherOrder dispersion medium implementation; the second-order dispersion amount provided by the second-order dispersion medium is satisfied
Figure FDA0003693550890000051
Figure FDA0003693550890000052
Wherein f is 0 Is input optical frequency comb repetition frequency v' 1 Is a frequency division regulation factor of five, u' 1 Is a frequency division regulation factor of six, v' 2 Is a frequency division regulation factor of seven, u' 2 Is a frequency division regulation factor of eight, v' 1 、u′ 1 、v′ 2 、u′ 2 Are all positive integers; r' 1 ＝q′ 1 /v′ 1 、r′ 2 ＝q′ 2 /v′ 2 A first frequency-dividing factor and a second frequency-dividing factor which are input optical frequency comb repetition frequencies respectively;
(4) A third phase modulator (8) and a fourth phase modulator (9) are used for respectively applying a third time domain second order phase modulation and a fourth time domain second order phase modulation to the two paths of optical pulse signals passing through the frequency domain second order phase modulation module (7);
for the first working mode, the optical pulse signals modulated by the first time domain second-order phase modulation and the frequency domain second-order phase modulation are subjected to fourth time domain second-order phase modulation by a fourth phase modulator (9), and the related modulation waveform is as follows:
Figure FDA0003693550890000053
the second-order phase modulation of the time domain and the second-order phase modulation of the frequency domain are carried out on the optical pulse signals through a third phase modulator (8), and the related modulation waveform is as follows:
Figure FDA0003693550890000054
wherein s' 1 Is a frequency division regulation factor of nine, and is composed of u' 1 And v' 1 Obtained according to the following formula:
Figure FDA0003693550890000055
s′ 2 is a frequency division regulation factor of ten, and is composed of u' 2 And v' 2 Obtained according to the following formula:
Figure FDA0003693550890000056
sigma and a second-order dispersion amount beta provided by the frequency domain second-order phase modulation module (7) 2 The relationship of (1) is:
Figure FDA0003693550890000057
for the second mode of operation, it is necessary to interchange the phase modulation waveform three and the phase modulation waveform four, while depending on the second-order dispersion β experienced 2 Is assigned to sigma
(5) Respectively outputting a first optical frequency comb and a second optical frequency comb after time domain second-order phase modulation IV and time domain second-order phase modulation III, wherein the repetition frequency of the first optical frequency comb and the second optical frequency comb is the repetition frequency f of the input optical frequency comb 0 The integer multiple frequency division results of f rep1 ＝f 0 /r′ 1 And f rep2 ＝f 0 /r′ 2 (ii) a And (4) outputting the double optical frequency comb with the flexibly adjustable repetition frequency by adjusting the first frequency division regulation factor related to the time domain and frequency domain second-order phase modulation in the steps (2), (3) and (4).
CN202210667799.4A 2022-06-14 2022-06-14 Double-optical-frequency comb generation device and method with adjustable repetition frequency Pending CN115185136A (en)

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Publication number Priority date Publication date Assignee Title
CN116047535A (en) * 2022-12-30 2023-05-02 电子科技大学 Dual-optical frequency comb time-of-flight ranging system based on dispersion Fourier transform

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116047535A (en) * 2022-12-30 2023-05-02 电子科技大学 Dual-optical frequency comb time-of-flight ranging system based on dispersion Fourier transform
CN116047535B (en) * 2022-12-30 2024-03-22 电子科技大学 Dual-optical frequency comb time-of-flight ranging system based on dispersion Fourier transform

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