CN103941515B - Comb frequency interval can the frequency comb generation device of frequency sweep and production method - Google Patents

Abstract

The invention provides a kind of comb frequency interval can the frequency comb generation device of frequency sweep, signal generator forms two-way output after microwave power divider, wherein, first via output is connected with electro-optic phase modulator after the first wide-band microwave power amplifier, second road output is connected with photoelectricity intensity modulator after sequentially passing through adjustable microwave delay line and the second wide-band microwave power amplifier, continuous-wave laser sequentially passes through electro-optic phase modulator and the output of photoelectricity intensity modulator of cascade, and photoelectricity intensity modulator is provided with direct current biasing.Additionally provide production method simultaneously.The present invention realizes the continuous frequency sweep in the broadband of comb frequency interval and accurately arbitrarily regulation；Produced frequency comb phase place, frequency stable；Produce frequency comb sufficient center wavelength accuracy, and tunable；Equipment scheme is simple, and cost is relatively low；Meet the application demand in the fields such as optical measurement, optical imagery, laser radar, laser spectroscopy, Fibre Optical Sensor, optic communication and Microwave photonics.

Description

Comb frequency interval can the frequency comb generation device of frequency sweep and production method

Technical field

The present invention relates to optic communication and field of optical measuring technologies a kind of comb spacing frequency can wideband phase continuous The production method of the optical frequency com of frequency sweep, specifically, is a kind of employing cascade electrooptic phase-modulator and photoelectricity Intensity modulator, it is achieved comb spacing frequency can the comb frequency interval of wideband phase cline frequency scanning can frequency sweep Frequency comb generation device and production method, during whole frequency sweep, the comb flatness of frequency comb keeps constant.

Background technology

The optical frequency com that frequency interval is precise and stable, comb is relevant be widely used in laser measurement, optical imagery, The fields such as laser radar, laser spectroscopy, Fibre Optical Sensor, optic communication and Microwave photonics.Comb power is smooth, The optical frequency com that spectral range width, phase coherence and comb frequency interval can arbitrarily control continuously, in random waveform Generator, the microwave photon filter of broadband Frequency Adjustable, wideband adjustable microwave/millimeter wave/terahertz signal generation, In the generation of the synchronization between multiple optical frequency coms and phase-locked, optical measurement and ultra broadband continuous spectrum optical frequency com All there is urgent demand.

At present, main comb spacing frequency tunable optical frequency comb producing method has the optical fiber based on image intensifer The cascade electrooptic phase-modulation of loop, mode-locked laser and radio frequency signals drive three kinds.

Electrooptic modulator, based on the optical fiber loop of image intensifer, is positioned over inside loop by the first, by circulation The mode of frequency shift (FS) produces a plurality of comb, and by the fiber amplifier within optical fiber loop and optical band pass filter Compensation loop loss and control frequency comb bandwidth respectively.Its comb interval and modulator driving signal frequency and fiber optic loop The frequency of oscillation on road is related to, and needs the tune carrying out image intensifer and optical filter of coupling during regulation comb frequency interval Joint, therefore can not carry out phase coherence to comb spacing frequency and continuously adjust；And put by the light in optical fiber loop Big device is circulated amplification, and the frequency comb noise coefficient producing after repeatedly accumulating incrementally increases.

The second, uses nonlinear dielectric to carry out spectrum widening to mode-locked laser, and the broadband producing phase coherence surpasses Continuous spectrum, its comb frequency interval can be tuned by the length in regulation vibration chamber.Through to prior art The retrieval discovery of document, existing carries out continuous frequency sweep to mode-locked laser comb spacing frequency (i.e. repetition rate) The implementation of regulation mainly has two kinds.Brian R.Washburn et al. is published in scholarly journal " Optics Express " scientific paper " Fiber-laser-based frequency comb with in (" optics news flash ") In a tunable repetition rate " (based on the repetition rate tunable frequency comb of optical fiber laser), Propose the chamber inner fiber delay line utilizing motor to control, change the chamber length of mode-locked laser thus reach frequency tuning Purpose.The adjustable range of its comb frequency interval is 49.34-50.12MHz, and laser instrument can during whole tuning It to keep locked mode, is i.e. phase coherence.Holger Hundermark et al. is published in scholarly journal " Optics Express " scientific paper " Stable sub-85fs passively mode-locked in (" optics news flash ") (repetition rate is tunable for Erbiumfiber oscillator with tunable repetition rate " Sub-85 femtosecond passive mode-locking Er-doped fiber oscillators) in, propose by changing can adjust in mode-locked laser chamber The position of lens, thus it is long to change chamber, reaches the purpose of frequency tuning.Its adjustable range to frequency interval is 1.1MHz, can keep coherence stable between comb during whole tuning.Such scheme all can be to frequency comb Comb frequency interval carry out the relevant tuning of continuous print, but owing to mode-locked laser needs to carry out the steady of complexity to chamber Fixed control, limits the tunable range of chamber length, thus limits the tuning range of comb frequency interval at several MHz Rank, and need complicated cavity stability controlling mechanism.

The third, it is smooth that the cascade electrooptic phase-modulation of radio frequency signals drive can produce phase coherence, comb power Optical frequency com, its comb quantity producing is less slightly with first two mode, but its simple in construction, stability is high, and Comb frequency interval can directly accurately be regulated by the radiofrequency signal driving.But, in order to make the frequency comb of generation protect Maintain an equal level smooth, need control to cascade electro-optic phase and the driving signal of intensity modulator makes its phase matched, and difference is driven Need under dynamic frequency to recalibrate the phase relation driving signal.Therefore can not be real while keeping light comb flatness The continuous frequency sweep in broadband of existing comb spacing frequency.

Content of the invention

It is an object of the invention to overcome deficiency of the prior art, it is proposed that a kind of based on radio frequency signals drive cascade electrooptic The comb frequency interval of phase-modulator and photoelectricity intensity modulator can the frequency comb generation device of frequency sweep and production method, The optical frequency com phase coherence being produced by generation device, comb frequency interval can keep Phase Continuation in broadband range Ground frequency sweep, its optical frequency comb phase place producing, frequency stable, it is achieved mode is relatively simple, can meet optical measurement, optics The application demand in the fields such as imaging, laser radar, laser spectroscopy, Fibre Optical Sensor, optic communication and Microwave photonics.

The present invention is achieved by the following technical solutions.

According to an aspect of the invention, it is provided a kind of comb frequency interval can the frequency comb generation device of frequency sweep, bag Include signal generator, continuous-wave laser, electro-optic phase modulator, photoelectricity intensity modulator, microwave power divider, First wide-band microwave power amplifier, the second wide-band microwave power amplifier and adjustable microwave delay line, wherein, described Signal generator forms two-way output after microwave power divider, and wherein, first via output is through the first broadband Be connected with electro-optic phase modulator after microwave power amplifier, the second road output sequentially pass through adjustable microwave delay line and Being connected with photoelectricity intensity modulator after second wide-band microwave power amplifier, described continuous-wave laser sequentially passes through cascade Electro-optic phase modulator and photoelectricity intensity modulator output, described photoelectricity intensity modulator is provided with direct current biasing.

Preferably, time delay correlator, optoelectronic receiver and sampling oscilloscope are also included, described photoelectricity intensity modulator Output be connected with time delay correlator, described time delay correlator is connected with optoelectronic receiver, described opto-electronic receiver Machine is connected with sampling oscilloscope.

Preferably, described signal generator uses microwave signal generator or high-speed pulse signal generator.

According to another aspect of the present invention, providing a kind of comb frequency interval can the frequency comb generation side of frequency sweep Method, comprises the following steps:

Step 1, signal generator produces wideband frequency tunable signal and is divided into two-way by after microwave power divider, the One tunnel the first wide-band microwave power amplifier amplifies rear drive electro-optic phase modulator；Second tunnel postpones through adjustable microwave After line, then amplify through the second wide-band microwave power amplifier, drive photoelectricity intensity modulator；

Step 2, the optical carrier of continuous-wave laser output is adjusted through electro-optic phase modulator and the light electric strength of cascade Device processed, the bias point of regulation photoelectricity intensity modulator makes output form smooth frequency comb；

Step 3, regulates variable delay line so that light electric delay difference is zero, it is achieved wideband phase mates；Now, signal The signal of generator output broadband frequency sweep, correspondingly, the comb spacing frequency of the frequency comb of photoelectricity intensity modulator output is also Frequency sweep change therewith, producing comb frequency interval can the frequency comb of broadband frequency sweep.

Preferably, in described step 2, the frequency of signal produced by the comb spacing frequency of frequency comb and signal generator Identical.

Preferably, also include step 4, described step 4 particularly as follows:

The comb frequency interval that step 3 produces can the frequency comb of broadband frequency sweep, through time delay correlator and optoelectronic receiver After, shown by sampling oscilloscope.

The comb frequency interval that the present invention provides can the frequency comb generation device of frequency sweep and production method, it exports frequency comb Comb flatness not with signal generator output signal frequency change and change, i.e. not with between the comb of frequency comb Change every frequency and change, stable spectral flatness can be kept during the frequency sweep of whole broadband；Make cascade electrooptic Between phase-modulator and photoelectricity intensity modulated, optical signal time delay and microwave-driven signal lag accurately mate.Use cascade Electro-optic phase modulator and photoelectricity intensity modulator, and accurately regulate optical signal and microwave-driven between two modulators Time delay between signal, it is achieved the wideband phase coupling of photoelectricity delay inequality, by the wideband phase of microwave-driven signal Cline frequency scans, it is achieved the method for comb spacing frequency wideband phase cline frequency therewith scanning optical frequency comb, During whole frequency sweep, optical frequency comb comb flatness keeps constant.

Compared with prior art, the method have the advantages that

1st, breach the restriction of tradition frequency comb producing method, due to microwave signal generator frequency stable, accurately, Can arbitrarily control to adjust, it is achieved that the continuous frequency sweep in broadband of comb frequency interval and accurately arbitrarily regulation；

2nd, the frequency comb stability being driven modulator to produce by microwave signal is high, and produced frequency comb phase place, frequency are steady Fixed；

3rd, high stability or tunable continuous light laser instrument can be used as light carrier, therefore cardiac wave in produced frequency comb Long stable and tunable；

4th, equipment scheme is simple, and cost is relatively low；

5th, breach the restriction of tradition optical frequency comb, meet optical measurement, optical imagery, laser radar, laser spectrum The application demand in the fields such as, Fibre Optical Sensor, optic communication and Microwave photonics.

Brief description

By reading the detailed description made non-limiting example with reference to the following drawings, other of the present invention are special Levy, objects and advantages will become more apparent upon:

Fig. 1 is that comb frequency interval of the present invention can the frequency comb generation device structure principle chart of frequency sweep；

Fig. 2 is the Method And Principle figure of photoelectricity delay inequality wideband phase coupling；

Fig. 3 is photoelectricity delay inequality wideband phase coupling schematic diagram, and wherein, (a) is photoelectricity delay inequality τ_SShow when ≠ 0 Being intended to, (b) is photoelectricity delay inequality τ_SSchematic diagram when=0；

Fig. 4 is the method flow diagram of microwave-driven signal wideband phase coupling；

Fig. 5 is by being produced frequency comb comb frequency interval broadband frequency sweep design sketch in the embodiment of the present invention；

Fig. 6 by the embodiment of the present invention the spectrum of generation frequency comb, wherein, (a) is that comb spacing frequency is for Spectrogram during low 8.5GHz, (b) is the spectrogram that comb spacing frequency is during the highest 19.0GHz；

In figure: 101 is semiconductor laser, 102 is Mach once moral electro-optic phase modulator, and 103 is horse Conspicuous once moral photoelectricity intensity modulator, 104 is 3-dB microwave power divider, and 105 is that the first adjustable gain broadband is micro- Power Amplifier, 106 is the second adjustable gain wide-band microwave power amplifier, and 107 is adjustable microwave delay line, 108 is microwave signal generator, and 109 is high-speed pulse signal generator, and 110 is Mach once moral time delay correlator, 111 is adjustment of balance optoelectronic receiver, and 112 is high-speed sampling oscillograph, and 113 is direct current biasing.

Detailed description of the invention

Below embodiments of the invention are elaborated: the present embodiment carries out reality under premised on technical solution of the present invention Execute, give detailed embodiment and concrete operating process.It should be pointed out that, the ordinary skill people to this area For Yuan, without departing from the inventive concept of the premise, can also make some deformation and improve, these broadly fall into this Bright protection domain.

Please refer to Fig. 1 to Fig. 6.

Present embodiments provide a kind of comb frequency interval can the frequency comb generation device of frequency sweep, including signal generator, Continuous-wave laser, electro-optic phase modulator, photoelectricity intensity modulator, microwave power divider, the first wide-band microwave work( Rate amplifier, the second wide-band microwave power amplifier and adjustable microwave delay line, wherein, described signal generator passes through Forming two-way output after microwave power divider, wherein, first via output is through the first wide-band microwave power amplifier Being connected with electro-optic phase modulator afterwards, the second road output sequentially passes through adjustable microwave delay line and the second wide-band microwave work( Being connected with photoelectricity intensity modulator after rate amplifier, described continuous-wave laser sequentially passes through the electro-optic phase modulation of cascade Device and the output of photoelectricity intensity modulator, described photoelectricity intensity modulator is provided with direct current biasing.

Further, time delay correlator, optoelectronic receiver and sampling oscilloscope are also included, described photoelectricity intensity modulated The output of device is connected with time delay correlator, and described time delay correlator is connected with optoelectronic receiver, and described photoelectricity connects Receipts machine is connected with sampling oscilloscope.

Further, described signal generator uses microwave signal generator or high-speed pulse signal generator.

A kind of above-mentioned comb frequency interval that the present embodiment provides can the frequency comb generation device of frequency sweep, its frequency comb is produced Generation method, comprises the following steps:

Step 1, signal generator produces wideband frequency adjustable microwave signal and is divided into two-way by after microwave power divider, The first via amplifies rear drive electro-optic phase modulator through the first wide-band microwave power amplifier；Second tunnel is prolonged through adjustable microwave After slow line, then amplify through the second wide-band microwave power amplifier, drive photoelectricity intensity modulator；

Step 2, the optical carrier of continuous-wave laser output is adjusted through electro-optic phase modulator and the light electric strength of cascade Device processed, the bias point of regulation photoelectricity intensity modulator makes output form smooth frequency comb；

Step 3, regulates variable delay line so that light electric delay difference is zero, it is achieved wideband phase mates；Now, signal The signal of generator output broadband frequency sweep, correspondingly, the comb spacing frequency of the frequency comb of photoelectricity intensity modulator output is also Frequency sweep change therewith, producing comb frequency interval can the frequency comb of broadband frequency sweep.

Further, in described step 2, the comb spacing frequency of frequency comb and microwave signal produced by signal generator Frequency identical.

Further, also include step 4, described step 4 particularly as follows:

The comb frequency interval that step 3 produces can the frequency comb of broadband frequency sweep, through time delay correlator and optoelectronic receiver After, shown by sampling oscilloscope.

Below in conjunction with the accompanying drawings the present embodiment is elaborated.

In the present embodiment,

Continuous-wave laser can use semiconductor laser；

Electro-optic phase modulator can use Mach once moral electro-optic phase modulator；

Photoelectricity intensity modulator can use Mach once moral photoelectricity intensity modulator；

Microwave power divider can use 3-dB microwave power divider；

First wide-band microwave power amplifier and the second wide-band microwave power amplifier all can use adjustable gain width Band microwave power amplifier；

Time delay correlator can use Mach once moral time delay correlator；

Optoelectronic receiver can use adjustment of balance optoelectronic receiver；

Sampling oscilloscope can use high-speed sampling oscillograph；

Fig. 1 is the theory diagram of the present invention.The present embodiment provide comb frequency interval can frequency sweep frequency comb produce dress Put, specifically include that semiconductor laser, Mach once moral electro-optic phase modulator, Mach Zeng Deguang electric strength Modulator, 3-dB microwave power divider, wide-band microwave power amplifier, adjustable microwave delay line, high-speed pulse signal Generator or microwave signal generator, Mach once moral time delay correlator, high speed optoelectronic receiver, high-speed sampling oscillograph. First with high-speed pulse signal generator or microwave signal generator, Mach once moral time delay correlator, high speed optoelectronic reception Machine, high-speed sampling oscillograph make the wideband phase of the photoelectricity delay inequality between cascaded modulator mate, and i.e. make described τ_S=0, re-using the described comb spacing frequency broadband of microwave signal generator generation can frequency sweep optical frequency com.

Particularly as follows:

First, Fig. 2 is photoelectricity delay inequality wideband phase matching process schematic diagram: on high-speed pulse signal generator 109 produces The time of liter is the 10MHz square-wave signal of 30ps, is divided into two-way, a road after 3-dB microwave power divider 104 It is directly inputted to adjustable gain wide-band microwave power amplifier 105 amplified driving Mach once moral electro-optic phase modulator 102, another road is being input to adjustable gain wide-band microwave power amplifier 106 after first passing through adjustable microwave delay line 107 Amplified driving Mach once moral photoelectricity intensity modulator 103.The light of narrow linewidth semiconductor laser 101 output Carrier wave, after Mach once moral electro-optic phase modulator 102 and Mach once moral photoelectricity intensity modulator 103 modulation of cascade, It is input to high speed optoelectronic receiver 111 after the Mach once moral time delay correlator 110 that time delay is Δ t=100ps, pass through Its output observed by high-speed sampling oscillograph 112.

2nd, as shown in Fig. 3 (a), adjustable microwave delay line is regulated, as photoelectricity delay inequality τ_SWhen ≠ 0, Mach Zeng Deyan When correlator two-arm signal at a cycle memory in π phase shift, therefore create and square-wave signal cycle phase at output The burst pulse of same 100ps.As shown in Fig. 3 (b), as photoelectricity delay inequality complete wideband phase coupling, i.e. τ_SWhen=0, There is not π phase shift in the two-arm signal of Mach once moral time delay correlator, does not therefore have narrow pulse signal at output.But, Due to limited Rise Time of Square Wave and receiver bandwidth, output pulse power is with τ_SReduction and reduce.Pulse power And τ_SRelative to wideband phase match point variation tendency as shown in Figure 4, when pulse power is minimum, then carry out further It is fine-tuned, the wideband phase coupling of photoelectricity delay inequality can be realized.

Three as it is shown in figure 1, in the present embodiment, and producing comb spacing frequency broadband can the driving letter of frequency sweep optical frequency com Number be microwave signal generator 108, substitute in Part I (Fig. 2) high-speed pulse signal generator 109, it produces Raw wideband frequency adjustable microwave signal is divided into two-way after 3-dB power splitter, and a road is through adjustable gain wide-band microwave It is four times of phase-modulator V that power amplifier 105 is amplified to peak-to-peak value_π-PMVoltage rear drive phase-modulator 102；Separately One tunnel is after tunable microwave delayer, and being amplified to peak-to-peak value by adjustable gain microwave power amplifier 106 is twice Intensity modulator V_π-IMVoltage rear drive intensity modulator 103.Regulation adjustable microwave delayer is to described in step (2) Light electric delay wideband phase match point, the direct current biasing 113 of adjusting strength modulator, forms smooth frequency comb simultaneously Output signal.

4th, microwave signal generator is regulated so that the microwave signal of output is at the 8.5GHz more than an octave extremely Frequency sweep in the range of 19.0GHz, output comb spacing frequency broadband can frequency sweep optical frequency comb as shown in Figure 5.Its comb is smooth Degree is maintained in 4dB in whole swept frequency range.

5th, Fig. 6 (a) and (b) are that optical frequency comb is respectively minimum 8.5GHz and the highest 19.0GHz at comb spacing frequency When spectrogram.

6th, in the present embodiment during photoelectricity delay inequality deviation wideband phase match point, output frequency comb is at whole comb interval frequency Flatness change in rate swept frequency range.When not at optimal wideband phase match point, the flatness of output frequency comb is at comb In the range of the frequency-swept of space of teeth, change is acutely.Under actual conditions, due to finite rise time described in step (2) and Receiver bandwidth makes the precision of wideband phase match point limited, and the non-linear of wideband power amplifer can introduce additionally simultaneously Frequency harmonics, and the changing with drive frequency variations of modulator half-wave voltage, cause output frequency comb entirely The flatness having 4dB in comb spacing frequency swept frequency range changes.

7th, as a example by microwave signal generator, the present embodiment provide comb frequency interval can frequency sweep frequency comb produce Method, particularly as follows:

Step 1, uses the laser of continuous light laser instrument output as light carrier, the successively electro-optic phase modulation through cascade Device and photoelectricity intensity modulator, export frequency comb signal；Wherein, the electro-optic phase modulator of described cascade and light electric strength Modulator is driven by same microwave signal generator, and driving frequency is identical；Described microwave signal generator produces After microwave signal is amplified by microwave power amplifier, drive electro-optic phase modulator and photoelectricity intensity modulator respectively；

Output frequency comb signal is represented by:

$E_{\mathrm{out}}\left(t\right)=\frac{E_c}{2}\exp \left(j{\mathrm{\ω}}_{c}t\right)\exp \left[\mathrm{j\π}{\mathrm{\β}}_{\mathrm{PM}}\cos \left({\mathrm{\ω}}_{s}t\right)\right]\{1+\exp [\mathrm{j\π}({\mathrm{\β}}_{\mathrm{DC}}+{\mathrm{\β}}_{\mathrm{IM}}\cos \left({\mathrm{\ω}}_s(t+{\mathrm{\τ}}_S)\right))\left]\right\}$

Wherein, E_cFor the intensity of optical carrier, j is imaginary unit, and t is the time, and π is pi, ω_cFor light carrier The angular frequency of signal, ω_s=2πf_sFor driving the angular frequency of signal, f_sFor driving the frequency of signal, β_PM、β_IMAnd β_DC It is respectively phase-modulator, intensity modulator and intensity modulator direct current biasing to modulate relative to the normalization of its half-wave voltage The degree of depth, τ_S=τ_O-τ_EIt is that between the modulator of two cascades, optical signal postpones τ_OWith microwave-driven signal delay τ_ETime delay Difference.The comb frequency interval of described frequency comb signal is for driving frequency f of microwave signal_s, the comb of described frequency comb signal Flatness and the product ω of driving signal frequency and photoelectricity delay inequality_sτ_SRelated.

Step 2, photoelectricity delay inequality τ between the electro-optic phase modulator and photoelectricity intensity modulator of described cascade_S=0, When i.e. achieving wideband phase coupling to described photoelectricity delay inequality, described frequency comb signal is:

$E_{\mathrm{out}}\left(t\right)=\frac{E_c}{2}{\left(j\right)}^n\exp \left[j({\mathrm{\ω}}_c+n{\mathrm{\ω}}_s)t\right]\underset{n=-\∞}{\overset{+\∞}{\mathrm{\Σ}}}\{J_n\left(\mathrm{\π}{\mathrm{\β}}_{\mathrm{PM}}\right)+\exp \left(\mathrm{j\π}{\mathrm{\β}}_{\mathrm{DC}}\right)J_n[\mathrm{\π}({\mathrm{\β}}_{\mathrm{PM}}+{\mathrm{\β}}_{\mathrm{IM}})\left]\right\}$

Wherein, n is comb numbering, J_nX () represents n rank one class Bessel function.Now, the comb of described frequency comb is put down Smooth degree is only related to the direct current biasing of the modulators modulate degree of depth and intensity modulator, and unrelated with the frequency driving signal. Regulation modulation depth and direct current biasing, it is possible to obtain the smooth optical frequency comb of comb.

Step 3, on the basis of step 1 and step 2, enters to the frequency of the microwave signal that microwave signal generator produces The continuous frequency sweep of row, can produce the frequency comb of the continuous frequency sweep of comb frequency interval, keeps the comb of described frequency comb to put down simultaneously Smooth degree.

On the basis of technique scheme, described microwave signal generator can produce broadband frequency sweep microwave signal.Described The regulation of photoelectricity delay inequality between cascaded modulator, is realized by microwave delay line.

Above the specific embodiment of the present invention is described.It is to be appreciated that the invention is not limited in Stating particular implementation, those skilled in the art can make various deformation or modification within the scope of the claims, This has no effect on the flesh and blood of the present invention.

Claims (6)

1. a comb frequency interval can the frequency comb generation device of frequency sweep, it is characterised in that include signal generator, Continuous-wave laser, electro-optic phase modulator, photoelectricity intensity modulator, microwave power divider, the first wide-band microwave work( Rate amplifier, the second wide-band microwave power amplifier and adjustable microwave delay line, wherein, described signal generator passes through Forming two-way output after microwave power divider, wherein, first via output is through the first wide-band microwave power amplifier Being connected with electro-optic phase modulator afterwards, the second road output sequentially passes through adjustable microwave delay line and the second wide-band microwave work( Being connected with photoelectricity intensity modulator after rate amplifier, described continuous-wave laser sequentially passes through the electro-optic phase modulation of cascade Device and the output of photoelectricity intensity modulator, described photoelectricity intensity modulator is provided with direct current biasing.

2. comb frequency interval according to claim 1 can the frequency comb generation device of frequency sweep, it is characterised in that Also include time delay correlator, optoelectronic receiver and sampling oscilloscope, the output of described photoelectricity intensity modulator with prolong When correlator be connected, described time delay correlator is connected with optoelectronic receiver, described optoelectronic receiver with sampling oscillography Device is connected.

3. comb frequency interval according to claim 1 and 2 can the frequency comb generation device of frequency sweep, its feature Being, described signal generator uses microwave signal generator or high-speed pulse signal generator.

4. a comb frequency interval can the frequency comb production method of frequency sweep, it is characterised in that comprise the following steps:

Step 1, signal generator produces wideband frequency tunable signal and is divided into two-way by after microwave power divider, the One tunnel the first wide-band microwave power amplifier amplifies rear drive electro-optic phase modulator；Second tunnel postpones through adjustable microwave After line, then amplify through the second wide-band microwave power amplifier, drive photoelectricity intensity modulator；

Step 2, the optical carrier of continuous-wave laser output is adjusted through electro-optic phase modulator and the light electric strength of cascade Device processed, the bias point of regulation photoelectricity intensity modulator makes output form smooth frequency comb；

Step 3, regulates variable delay line so that light electric delay difference is zero, it is achieved wideband phase mates；Now, signal The signal of generator output broadband frequency sweep, correspondingly, the comb spacing frequency of the frequency comb of photoelectricity intensity modulator output is also Frequency sweep change therewith, producing comb frequency interval can the frequency comb of broadband frequency sweep.

5. comb frequency interval according to claim 4 can the frequency comb production method of frequency sweep, its feature exists In, in described step 2, the comb spacing frequency of frequency comb is identical with the frequency of signal produced by signal generator.

6. the comb frequency interval according to claim 4 or 5 can the frequency comb production method of frequency sweep, its feature Be, also include step 4, described step 4 particularly as follows:

The comb frequency interval that step 3 produces can the frequency comb of broadband frequency sweep, through time delay correlator and optoelectronic receiver After, shown by sampling oscilloscope.