CN1302268C - Method and apparatus for measuring beat frequency of low light level light source - Google Patents
Method and apparatus for measuring beat frequency of low light level light source Download PDFInfo
- Publication number
- CN1302268C CN1302268C CNB2004100460069A CN200410046006A CN1302268C CN 1302268 C CN1302268 C CN 1302268C CN B2004100460069 A CNB2004100460069 A CN B2004100460069A CN 200410046006 A CN200410046006 A CN 200410046006A CN 1302268 C CN1302268 C CN 1302268C
- Authority
- CN
- China
- Prior art keywords
- beat frequency
- light source
- attenuator
- signal
- low light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The present invention discloses a method and a device for measuring the beat frequency of weak light sources, which comprises the steps that after attenuated, a laser is divided into two beams; after interference optical filtration, the two beams are input to two single photon detectors, wherein after passing through a discriminating amplifier, one of the beams directly enters a time amplitude converter; after passing through the discriminating amplifier, the other beam passes through a delay line and then is input to the time amplitude converter; subsequently, a signal output by the time amplitude converter is input to a multichannel analyzer; the beat frequency data of a light source of a time domain can be obtained by the accumulation on the multichannel analyzer; the beat frequency of the weak light source of a frequency domain can be obtained after analyzed by Fourier number value. The present invention can measure the beat frequency of the weak light source under the condition that a spectrum analyzer is not used; besides, the measure is not limited by the response time of a detector and a pre-amplifier.
Description
Technical field
The present invention relates to a kind of method and device that the beat frequency of low light level light source is measured.
Background technology
The principle of the method for traditional measurement light source beat frequency is as follows: a detector is surveyed the light source with certain intensity, and the photosignal of its output is analyzed by circuit by spectrum analyzer through behind the prime amplifier, thereby obtains the beat frequency of light source.Its detection process is subjected to the restriction of the response time of detector, prime amplifier and spectrum analyzer, and the frequency range of this method institute energy measurement is in the GHz magnitude.And be subjected to the influence of inevitable shot noise, this method is the energy measurement low light level not.
Fu in 1991 is coiled the article " Observation of the beat between two independent light sourcesby a method of time-delayed laser-induced double gratings " of people such as inscription, Mi Xin on " Optics Letters " the 16th rolls up the 1526th page-1528 pages and has been proposed a kind of method of measuring the beat frequency between two arbitrary sources, and its time resolution can reach 10
-12The magnitude of second.But this method needs a kind of third-order non-linear medium, forms two and overlap independently grating in medium, therefore needs the pulsed laser light source of high power density usually.Z.Y.Ou and L.Mandel two people once on the 54th page-57 pages of " Physical Review Letters " the 61st volumes in 1988, published an article " Observation of spatial quantum beating with separated photodetectors ", propose with the measuring method of coincidence counting measure parameter down the photon that produces of conversion between beat frequency, its principle is to utilize under the parameter photon that conversion produces in time correlativity, change the relative length of the right optical path of photon, measure coincidence counting, obtain counting change curve, and then obtain beat frequency information with the optical path difference.The beat frequency rate of this method institute energy measurement can be up to 10
5GHz, high thousands of times of the response frequency of ratio detection device.But this method requires two-beam will be correlated with in time, and wants the scanning optical path difference.
Because the limitation of above several method wants to survey the beat frequency of the low light level, and is not subjected to detector, prime amplifier and the restriction of spectrum analyzer response time, need seek way in addition.
Summary of the invention
At problems of the prior art, the purpose of this invention is to provide a kind of method of measuring low light level light source beat frequency; Further, also provide a kind of device that does not rely on the measurement low light level light source beat frequency of frequency spectrograph.
For achieving the above object, a kind of method of measuring low light level light source beat frequency of the present invention comprises the steps: that (i) decays into the utmost point low light level that intensity is single photon stream with LASER Light Source through attenuator, is divided into two bundles with beam splitter with the low light level again; After (ii) the two bundle low light levels being filtered parasitic light through light filter, introduce first single-photon detector and second single-photon detector respectively, the photon that arrives is made response and produced a negative pulse electric signal respectively; (iii) described negative pulse electric signal is differentiated the amplifier and the second discriminating amplifier through first respectively, and the negative NIM signal of outputting standard; (iv) the NIM signal of second detector output is introduced delay line; (V) the NIM signal input time-to-amplitude conversion instrument of first detector and second detector being exported respectively, time-to-amplitude conversion instrument responds to the NIM signal that successively arrives, and exports a positive square-wave signal; (vi) this square-wave signal is input into MCA, each signal is assigned on the location, corresponding road according to the amplitude size as a counting; (vii) through accumulating the count distribution histogram that obtains on the MCA, i.e. beat frequency curve map under the time domain; (viii) the data of beat frequency curve map are carried out the numerical value Fourier analysis, obtain the beat frequency under the frequency domain.
Further, described attenuator is an attenuator.
Further, described light filter is an interference filter.
Further, described beam splitter is a semi-transparent semi-reflecting lens.
A kind of device of measuring low light level light source beat frequency of realizing the method that the beat frequency of above-mentioned low light level light source is measured comprise attenuator, beam splitter, first attenuator, second attenuator, first light filter, second light filter, first single-photon detector, second single-photon detector, first differentiate amplifier, second differentiate amplifier, delay line, the time secondary conversion device and MCA; The output terminal of attenuator links to each other with the input end of beam splitter, output terminal of beam splitter with the time secondary conversion device an input end between be connected first attenuator, first light filter, first single-photon detector, first successively and differentiate amplifier, another output terminal of beam splitter with the time secondary conversion device another input end between be connected second attenuator, second light filter, second single-photon detector, second successively and differentiate amplifier, delay line, the time secondary conversion device output terminal link to each other with the input end of MCA; Behind LASER Light Source described attenuator of process and the beam splitter, become the low light level of two bundle single photon streams, wherein a branch of low light level filters parasitic light behind described first light filter, behind described first single-photon detector, produce a undersuing, again through described first differentiate amplifier after the negative NIM signal of a standard of output, be input to secondary conversion device when described at last; Another bundle low light level filters parasitic light through behind described second light filter, behind described second single-photon detector, produce a undersuing, again through described second differentiate amplifier after the negative NIM signal of a standard of output, and secondary conversion device when input is described behind delay line; Secondary conversion device responds to the NIM signal that successively arrives when described, and exports a positive square-wave signal, imports described MCA at last.
Further, described attenuator is an attenuator.
Further, described light filter is an interference filter.
Further, described beam splitter is a semi-transparent semi-reflecting lens.
The present invention both can measure the beat frequency of low light level light source not relying under the situation of spectrum analyzer, was not subjected to the restriction of the response time of detector and prime amplifier again.For existing general technology level, if the shelves of MCA are got location, 8k road, the time-to-amplitude conversion instrument range is elected minimum 50ns as, then each location, road correspondence of MCA time-delay of about 10ps, and measurable beat frequency rate can reach the magnitude of tens GHz.
Description of drawings
Fig. 1 is the auto-correlation computation schematic diagram;
Fig. 2 is the measurement mechanism structural representation of low light level light source beat frequency of the present invention.
Embodiment:
Below in conjunction with accompanying drawing embodiment is described in further detail:
Principle of the present invention is: as shown in Figure 1, utilize related function C
12(τ)=∫ I
1(t) I
2The characteristic of (t+ τ) dt, promptly related operation is two function I of comparison
1(t) and I
2(t) similarity peak value can occur at resemblance.The second order coherence function of two quantum light fields of definition is
C
12(τ)＝<:I
1(t)I
2(t+τ):>， (1)
I wherein
i(t) be distribution of light intensity, i=1 or 2.Can get through deriving,
C
12(τ)∝cos(ω
1-ω
2)τ]。(2)
In, ω
1, ω
2Be the angular frequency of light field, ω
1-ω
2Be the beat frequency of two light fields.If a branch of light contains the light field of a plurality of frequencies, so, auto-correlation computation C
11(τ)=∫ I
1(t) I
1The result of (t+ τ) dt will comprise the time dependent information of light intensity, i.e. beat frequency information.
When a branch of light being measured, can prove that this is measured as autocorrelation measurement with time-to-amplitude conversion instrument and MCA.Time-to-amplitude conversion instrument is such device: after its Start end and Stop end receive two input signals with relative delay τ respectively, export to the positive square-wave signal that amplitude of MCA is directly proportional with delay time T.After if the Start termination of time-to-amplitude conversion instrument is received a signal, before receiving next signal, the Stop end does not receive signal, then time-to-amplitude conversion instrument no signal output.If the Start termination of time-to-amplitude conversion instrument is received a signal, before receiving next signal, the Stop termination is received a plurality of signals, and then time-to-amplitude conversion instrument is exported a positive square-wave signal only to first Stop signal response.
To be a positive signal that amplitude is not waited be assigned to device on the people having a common goal location not as counting to MCA accordingly.The location, road and the signal amplitude of MCA are proportional, and promptly the relative delay τ of a pair of signal that receives with time-to-amplitude conversion instrument is directly proportional.So through accumulation after a while, the relation of counting that shows on the MCA and location, road is exactly the relation of counting and delay time T.
If the Start of time-to-amplitude conversion instrument end is P at the probability that t receives a photosignal constantly
1(t), receive that in the t+ τ moment Stop termination probability of a photosignal is P
2(t+ τ), corresponding time-delay is 2 τ for location, the road width of τ on the MCA
c, then behind counting of this location, road record of the t moment, the probability that increases a counting in the Δ t time is:
In the formula,
P
i(t)=η
iP
i' (t) (i=1 or 2), (4)
η wherein
iBe the detection efficiency of i single-photon detector, P
i' (t) be i single-photon detector receives a photon constantly at t probability.Here,
P
i′(t)＝DI
i(t) (5)
Wherein, D is a proportionality constant, and is relevant with the character that is detected light wavelength and used single-photon detector.So have,
P
12(τ)＝∫P
1(t)P
2(t+τ)dt∝∫I
1(t)I
2(t+τ)dt。(6)
As seen, time-to-amplitude conversion instrument and MCA are to autocorrelation measurement that a branch of light is measured as.The gained result contains the beat frequency information under the time domain, carries out can obtaining behind the numerical value Fourier analysis beat frequency under the frequency domain.
As shown in Figure 2, LASER Light Source 1 is that wavelength is the He-Ne laser instrument of 632.8nm, the laser of its generation is through becoming the low light level of unimolecule stream behind the attenuator 2, semi-transparent semi-reflecting lens 3 with 632.8nm is divided into two bundles with light beam again, enters first single-photon detector 51 and second single-photon detector 52 after filtering parasitic light through first interference filter 41 and second interference filter 42 respectively; First single-photon detector 51 and second single-photon detector 52 are with a certain probability, and promptly detector responds to the photon that arrives to the quantum efficiency of this wave band photon, and each response provides a negative pulse electric current with regard to correspondence.After the negative pulse electric current differentiates that through first amplifier 61 and second is differentiated amplifier 62, output corresponding standard NIM signal.First differentiates that the NIM signal of amplifier output directly is input into Start one end of time-to-amplitude conversion instrument 8, behind the NIM signal process delay line 7 of the second discriminating amplifier output, and Stop one end of input time-to-amplitude conversion instrument 8.8 pairs of NIM signals that successively arrive of time-to-amplitude conversion instrument (the corresponding Stop signal of Start signal) respond, every response is once just corresponding to provide a positive square-wave signal, and be directly proportional the time delay of the relative Start signal with the Stop signal of the size of its amplitude.Behind this square-wave signal input MCA 9, be assigned to according to the big young pathbreaker of signal amplitude on the location, road of a correspondence, as a counting.The square-wave signal that amplitude does not wait is assigned on the corresponding not people having a common goal location, and the square-wave signal that amplitude equates will be assigned on the corresponding location, same road.Through accumulation after a while, at the beat frequency image that just forms on the MCA 9 under the time domain, the last beat frequency that just can obtain light source under the frequency domain again through the numerical value Fourier analysis.
The present invention is suitable equally to other LASER Light Source.
Claims (8)
1, a kind of method of measuring low light level light source beat frequency is characterized in that, comprises the steps: that (i) decays into the utmost point low light level that intensity is single photon stream with LASER Light Source through attenuator, is divided into two bundles with beam splitter with the low light level again; After (ii) the two bundle low light levels being filtered parasitic light through light filter, introduce first single-photon detector and second single-photon detector respectively, the photon that arrives is made response and produced a negative pulse electric signal respectively; (iii) described negative pulse electric signal is differentiated the amplifier and the second discriminating amplifier through first respectively, and the negative NIM signal of outputting standard; (iv) the NIM signal of second detector output is introduced delay line; (the NIM signal input time-to-amplitude conversion instrument of v) first detector and second detector being exported respectively, time-to-amplitude conversion instrument responds to the NIM signal that successively arrives, and exports a positive square-wave signal; (vi) this square-wave signal is input into MCA, each signal is assigned on the location, corresponding road according to the amplitude size as a counting; (vii) through accumulating the count distribution histogram that obtains on the MCA, i.e. beat frequency curve map under the time domain; (viii) the data of beat frequency curve map are carried out the numerical value Fourier analysis, obtain the beat frequency under the frequency domain.
2, a kind of method of measuring low light level light source beat frequency according to claim 1 is characterized in that, described attenuator is an attenuator.
3, a kind of method of measuring low light level light source beat frequency according to claim 1 is characterized in that, described light filter is an interference filter.
4, a kind of method of measuring low light level light source beat frequency according to claim 1 is characterized in that, described beam splitter is a semi-transparent semi-reflecting lens.
5, a kind of device of measuring low light level light source beat frequency, it is characterized in that, comprise attenuator, beam splitter, first attenuator, second attenuator, first light filter, second light filter, first single-photon detector, second single-photon detector, first differentiate amplifier, second differentiate amplifier, delay line, the time secondary conversion device and MCA; The output terminal of attenuator links to each other with the input end of beam splitter, output terminal of beam splitter with the time secondary conversion device an input end between be connected first attenuator, first light filter, first single-photon detector, first successively and differentiate amplifier, another output terminal of beam splitter with the time secondary conversion device another input end between be connected second attenuator, second light filter, second single-photon detector, second successively and differentiate amplifier, delay line, the time secondary conversion device output terminal link to each other with the input end of MCA; Behind LASER Light Source described attenuator of process and the beam splitter, become the low light level of two bundle single photon streams, wherein a branch of low light level filters parasitic light behind described first light filter, behind described first single-photon detector, produce a undersuing, again through described first differentiate amplifier after the negative NIM signal of a standard of output, be input to secondary conversion device when described at last; Another bundle low light level filters parasitic light through behind described second light filter, behind described second single-photon detector, produce a undersuing, again through described second differentiate amplifier after the negative NIM signal of a standard of output, and secondary conversion device when input is described behind delay line; Secondary conversion device responds to the NIM signal that successively arrives when described, and exports a positive square-wave signal, imports described MCA at last.
6, a kind of device of measuring low light level light source beat frequency according to claim 5 is characterized in that, described attenuator is an attenuator.
7, a kind of device of measuring low light level light source beat frequency according to claim 5 is characterized in that, described light filter is an interference filter.
8, a kind of device of measuring low light level light source beat frequency according to claim 5 is characterized in that, described beam splitter is a semi-transparent semi-reflecting lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100460069A CN1302268C (en) | 2004-05-31 | 2004-05-31 | Method and apparatus for measuring beat frequency of low light level light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100460069A CN1302268C (en) | 2004-05-31 | 2004-05-31 | Method and apparatus for measuring beat frequency of low light level light source |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1584535A CN1584535A (en) | 2005-02-23 |
| CN1302268C true CN1302268C (en) | 2007-02-28 |
Family
ID=34601903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100460069A Expired - Fee Related CN1302268C (en) | 2004-05-31 | 2004-05-31 | Method and apparatus for measuring beat frequency of low light level light source |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1302268C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102243106B (en) * | 2011-04-06 | 2013-01-02 | 中国航空工业集团公司北京长城计量测试技术研究所 | Frequency-beating device for laser frequency measurement |
| CN102322964B (en) * | 2011-09-01 | 2012-12-12 | 哈尔滨工业大学 | Optical phase lock tracking method based on four-channel laser frequency demodulation phase demodulation technology and apparatus realizing method |
| CN102353463B (en) * | 2011-09-01 | 2012-11-21 | 哈尔滨工业大学 | Four-channel detection technology based laser frequency and phase discrimination method and device realizing same |
| CN103712689B (en) * | 2014-01-02 | 2015-07-01 | 上海朗研光电科技有限公司 | Continuous laser device spectral line width measurement device based on optical frequency comb |
| CN108280437B (en) * | 2018-01-30 | 2021-06-15 | 四川新先达测控技术有限公司 | Pulse signal processing method and device and user terminal |
| CN110567594A (en) * | 2019-09-17 | 2019-12-13 | 中国计量科学研究院 | Precision laser wavelength measuring system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61241630A (en) * | 1985-04-19 | 1986-10-27 | Japan Aviation Electronics Ind Ltd | Optical beat frequency measuring device |
| JPH0572046A (en) * | 1991-09-17 | 1993-03-23 | Fujitsu Ltd | Optical beat frequency measuring apparatus |
| DE4139839A1 (en) * | 1991-12-03 | 1993-06-09 | Ernst-Moritz-Arndt-Universitaet, O-2200 Greifswald, De | Measuring beat frequency variations between two single mode lasers for distance measurement - sweeping wavelength of at least one laser and measuring and evaluating resulting phase angle change |
-
2004
- 2004-05-31 CN CNB2004100460069A patent/CN1302268C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61241630A (en) * | 1985-04-19 | 1986-10-27 | Japan Aviation Electronics Ind Ltd | Optical beat frequency measuring device |
| JPH0572046A (en) * | 1991-09-17 | 1993-03-23 | Fujitsu Ltd | Optical beat frequency measuring apparatus |
| DE4139839A1 (en) * | 1991-12-03 | 1993-06-09 | Ernst-Moritz-Arndt-Universitaet, O-2200 Greifswald, De | Measuring beat frequency variations between two single mode lasers for distance measurement - sweeping wavelength of at least one laser and measuring and evaluating resulting phase angle change |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1584535A (en) | 2005-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4905169A (en) | Method and apparatus for simultaneously measuring a plurality of spectral wavelengths present in electromagnetic radiation | |
| CN102384799B (en) | Frequency sweeping and data processing method based on Brillouin distributed fiber sensing system correlation detection scheme | |
| CN102288306B (en) | Method for simultaneously measuring output single-pulse energy and waveforms of lasers | |
| AU2002323371B2 (en) | Apparatus and a method for pulse detection and characterization | |
| EP0819924A3 (en) | Apparatus and method for measuring characteristics of optical pulses | |
| CN106643832A (en) | Phase-sensitive optical time-domain reflectometer based on linear frequency-modulation pulse and measurement method of phase-sensitive optical time-domain reflectometer | |
| CN111896137B (en) | Centimeter-level spatial resolution distributed optical fiber Raman sensing device and method | |
| CN111157097B (en) | Vibration signal detection method based on phase-sensitive optical time domain reflection system | |
| CN102768184A (en) | System for Young modulus measurement of film | |
| CN110274880A (en) | A kind of optical spectrum detecting method and system of high-precision spatial resolution | |
| CN104089710A (en) | Far field pulse signal-to-noise ratio measurement method and device based on temporal-spatial resolution | |
| CN110231332A (en) | The coherent anti-stokes raman scattering spectral device and method simplified using super steep filter plate | |
| CN101261224B (en) | Optical non-linear method for measuring material based on 4f phase coherent imaging system | |
| CN1302268C (en) | Method and apparatus for measuring beat frequency of low light level light source | |
| CN112525828B (en) | Mueller matrix measuring system and method based on optical time stretching | |
| CN108489959A (en) | A kind of coherent antistockes Raman spectroscopy scanning means and method | |
| CN111025306A (en) | Vibration positioning method and system based on phase-sensitive OTDR | |
| CN111239090A (en) | Method and system for measuring single-pulse laser-induced transient molecular fluorescence spectrum | |
| CN101520509B (en) | Method for comparatively measuring range of interframe of chaotic light time domain waveform | |
| CN105953929A (en) | Single-pulse width and energy measurement device | |
| CN104111243A (en) | Fluorescence ratio measuring system and method | |
| CN102494770B (en) | Accurate measuring device for atomic energy level | |
| CN114608697A (en) | Low-noise broadband distributed acoustic wave detection device and method based on FBG | |
| CN100354616C (en) | Chirped Pulse Longitudinal Diffraction Interferometer | |
| CN114739922A (en) | Multi-optical-frequency-comb dynamic spectrum detection system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20070228 Termination date: 20100531 |