CN103809166B - A kind of Michelson interference type spectral filter resonant frequency locking device and method - Google Patents

A kind of Michelson interference type spectral filter resonant frequency locking device and method Download PDF

Info

Publication number
CN103809166B
CN103809166B CN201410025286.9A CN201410025286A CN103809166B CN 103809166 B CN103809166 B CN 103809166B CN 201410025286 A CN201410025286 A CN 201410025286A CN 103809166 B CN103809166 B CN 103809166B
Authority
CN
China
Prior art keywords
frequency
angle
michelson interference
opd
reflecting mirror
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.)
Active
Application number
CN201410025286.9A
Other languages
Chinese (zh)
Other versions
CN103809166A (en
Inventor
刘�东
杨甬英
成中涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201410025286.9A priority Critical patent/CN103809166B/en
Publication of CN103809166A publication Critical patent/CN103809166A/en
Application granted granted Critical
Publication of CN103809166B publication Critical patent/CN103809166B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4816—Constructional features, e.g. arrangements of optical elements of receivers alone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/95—Lidar systems specially adapted for specific applications for meteorological use

Abstract

The invention discloses a kind of Michelson interference type spectral filter resonant frequency locking device and method.The present invention includes laser instrument divided beam system, Michelson interference-type filter system and Photodetection system；Laser instrument divided beam system includes laser instrument, collimator and extender device, the first spectroscope, the first reflecting mirror, the second reflecting mirror, the second spectroscope, the 3rd reflecting mirror；Michelson interference-type filter system includes a cube Amici prism, the 4th reflecting mirror, the 5th reflecting mirror；Photodetection system includes lens, the first photomultiplier tube, the second photomultiplier tube, the 3rd photomultiplier tube, difference amplifier, oscillograph；Concrete steps: 1. calculate the angle of incidence of two bundle probe beams；2. the angle of incidence of regulation two bundle probe beam；3. check oscillograph, it is judged that frequency-locked state；The present invention realizes simply, it is possible to avoids traditional locks frequency method to circuit and the complicated requirement of light path, thus has stronger system stability and robustness.

Description

A kind of Michelson interference type spectral filter resonant frequency locking device and method
Technical field
The invention belongs to laser radar technique field, particularly relate to a kind of Michelson (Michelson) interference type spectral filter resonance frequency locking device and method.
Background technology
High spectral resolution lidar is owing to have employed spectral filtering technology, after solving tradition Need many a priori assumptions just can be finally inversed by the deficiency of atmospheric parameter to scattering laser radar, thus Improve the precision of atmospheric remote sensing.In high spectral resolution lidar, spectral filter Use is an extremely crucial technology.By the high spectral resolution ability of spectral filter, energy Atmospheric backscatter spectrum by the composition of atmospheric aerosol scattering and will be scattered by atmospheric molecule Composition separate, thus can obtain atmospheric backscatter spectrum more details.In conjunction with phase The Remote Sensing Principles closed can be finally inversed by atmospheric backscatter coefficient, extinction coefficient etc. more accurately Atmospheric optics attribute.
At present, iodine molecule absorption filter because of the high filtration rate to atmospheric aerosol scattering signal, The high stability of spectral absorption characteristics and do not rely on the advantages such as mechanical alignment with incident illumination It is used in a lot of high spectral resolution lidar.But the absorption due to this type of wave filter Peak value (absorption resonance peak) is to be determined by the natural absorption mechanism of molecule, it is impossible to arbitrarily change Become it and use wave band, therefore the spectrum limiting laser radar is expanded.In order to solve this shortcoming, Michelson interference type spectral wave filter increasingly receives publicity and is progressively applied to laser radar In.Owing to have employed interference of light principle, the resonance of Michelson interference type spectral wave filter Frequency can be arranged on any optical maser wavelength interested, has widened the light of laser radar greatly Spectrum application.
But, the resonant frequency of Michelson interference type spectral wave filter but can not show a candle to iodine molecule Absorbing filter is the most stable.Temperature, external stress etc. all can cause the drift of resonant frequency. How Michelson interference type spectral filter resonance frequency is locked in the laser center of needs Frequency is its key technical problem for high spectral resolution lidar.Reporting In the document in road, all have employed the technology of frequency modulation(PFM) frequency locking.This technology is passed through will be for frequency locking Laser beam by the modulation of electrooptic modulator or acousto-optic modulator after, produce symmetrical Sideband frequency signal in original laser frequency both sides.This sideband signals and former laser signal pass through After interference type spectral wave filter to be locked, amplitude modulation(PAM) can be obtained on photodetector Voltage signal.One is finally needed to solve with the voltage signal of the signal synchronised driving manipulator Adjust this am signals, thus error signal when obtaining frequency losing lock.By by this error Signal feeds back to the frequency harmony equipment of interference type spectral wave filter, such as piezoelectric transducer (PZT), it is possible to the wave filter harmony again of locking will be lost to the laser frequency used. Although this technology is widely used, but the equipment that weak point is required is sufficiently complex.Such as At least need two electric light frequency modulators to reach reasonable modulation effect；In order to keep solving Adjust signal synchronization with modulator driving signal, generally require phase-locked loop circuit；Due to modulation frequency Rate is the most all in MHz magnitude, therefore detector needs the highest frequency response just can detect need The photosignal wanted.Each of which increases the circuit of this technology and the complexity of optics.
Summary of the invention
The invention aims to overcome above-mentioned the deficiencies in the prior art, reduce Michelson The device complexity of interference type spectral filter resonance frequency locking, it is proposed that a kind of Michelson Interference type spectral filter resonance frequency locking means.
The present invention make use of Michelson interference type spectral filter resonance frequency cleverly and enters Penetrating the dependence of the angle of incidence of laser, it is right that the probe beam matched by two bundle angle of incidence is come Michelson interference filter resonant frequency carries out real-time detection, once there is frequency losing lock fixed, Then can produce error signal and feed back to the frequency harmony equipment of wave filter with by its harmony again To frequency locking state.Owing to need not high frequency modulated and synchronous demodulation, therefore greatly reduce electricity Road, the complexity of light path.
A kind of Michelson interference type spectral filter resonant frequency locking device, including laser instrument Divided beam system, Michelson interference-type filter system and Photodetection system；
Laser instrument divided beam system includes laser instrument, collimator and extender device, the first spectroscope, first anti- Penetrate mirror, the second reflecting mirror, the second spectroscope, the 3rd reflecting mirror；Michelson interference-type is filtered Ripple device system includes a cube Amici prism, the 4th reflecting mirror, the 5th reflecting mirror, and wherein the 5th is anti- Penetrate mirror and the connection of frequency harmony plant machinery realizes resonant frequency and adjusts；Photodetection system includes Lens, the first photomultiplier tube, the second photomultiplier tube, the 3rd photomultiplier tube, difference are put Big device, oscillograph；
The collimated beam expander of laser beam that laser instrument is launched is expanded as angle pencil of ray directional light；Wide Parallel beam light is divided into two-way through the first spectroscope, and wherein a road is through the first spectroscope transmission After be emitted directly toward the Michelson interference filter system treating frequency locking as monitoring light beam；Another road After sequentially passing through the first reflecting mirror, the second reflecting mirror, then it is divided into two-way through the second spectroscope, its The middle first via is after the second spectroscope transmission, then reflects through the 3rd reflecting mirror with angle, θ2Enter Treat that the Michelson interference filter system of frequency locking is as probe beam；Second second point of tunnel Directly with angle, θ after light microscopic reflection1Enter and treat that the Michelson interference filter system of frequency locking is made For probe beam；Two-way probe beam and monitoring light beam are done through the Michelson treating frequency locking When relating to filter system, two-way probe beam and monitoring light beam are by Michelson interference filter Intrasystem cube of Amici prism of device is divided into two-way, a road after cube Amici prism transmission again by 4th reflecting mirror is reflected back a cube Amici prism, and is reflected into lens through a cube Amici prism； Another road is reflected back a cube Amici prism by the 5th reflecting mirror after cube Amici prism reflection again, And it is transmitted into lens through a cube Amici prism；Several roads light beam is by lens focus in its focal plane not Co-located also interferes respectively, and interference signal is respectively by the first photomultiplier tube, the second light Electricity multiplier tube, the 3rd photomultiplier tube are received and converted into the signal of telecommunication；By the first photomultiplier tube, The signal of telecommunication input difference amplifier of the second photomultiplier tube output, the output letter of difference amplifier Number feed back to frequency harmony equipment；And the output signal of telecommunication input oscillograph of the 3rd photomultiplier tube Signal is monitored as frequency-locked state.
A kind of Michelson interference type spectral filter resonant frequency locking means, including walking as follows Rapid:
Step 1. calculates the angle of incidence of two bundle probe beams；
Step 2. regulates the angle of incidence of two bundle probe beams；
Step 3. checks oscillograph, it is judged that frequency-locked state；
The angle of incidence of the two-way probe beam described in step 1 includes θ1And θ2；θ1And θ2Need to meet Mate requirement as follows:
θ1Choose the probe light needing to make Michelson interference filter incident to this angle The difference Δ OPD (θ of the optical path difference when optical path difference of bundle and 0 degree of angle incidence1) it is (n1+1/4)λ0, i.e.
ΔOPD(θ1)=(n1+1/4)λ0 (1)
Wherein, λ0It is laser center wavelength, n1It is that (recommendation is an integer to be selected 0～10)；ΔOPD(θ1) the structure of computational methods and Michelson interference filter used Relating to parameters；If the length that arm interfered by Michelson interference filter two is respectively d1And d2, Refractive index is respectively ρ1And ρ2, then Δ OPD (θ1) can calculate by following several formulas
OPD ( θ 1 ) = 2 · abs [ ρ 1 d 1 ( 1 - sin 2 θ 1 ρ 1 2 ) 1 / 2 - ρ 2 d 2 ( 1 - sin 2 θ 1 ρ 2 2 ) 1 / 2 ] - - - ( 2 a )
OPD (0)=2 abs (ρ1d1-ρ2d2) (2b)
ΔOPD(θ1)=abs [OPD (θ1)-OPD(0)] (2c)
Wherein, abs () expression takes absolute value, OPD (θ1) represent with angle, θ1Time incident The optical path difference of Michelson interference filter, Michelson when OPD (0) represents light normal incidence The optical path difference of interference filter；As long as have selected Integer n1After, simultaneous formula (1), (2) Solve θ1；
Want and θ1Match, incidence angle θ2It must is fulfilled for Michelson interference filter to this spy The change between optical path difference when the optical path difference of pin light beam and normal incidence:
ΔOPD(θ2)=(n2-1/4)λ0 (3)
In formula (3), n2For the integer that another is to be selected, it is 0～50 and than selected n1 Greatly, in like manner, Δ OPD (θ2) can calculate by following several formulas
OPD ( θ 2 ) = 2 · abs [ ρ 1 d 1 ( 1 - sin 2 θ 2 ρ 1 2 ) 1 / 2 - ρ 2 d 2 ( 1 - sin 2 θ 2 ρ 2 2 ) 1 / 2 ] - - - ( 4 a )
ΔOPD(θ2)=abs [OPD (θ2)-OPD(0)] (4b)
Wherein OPD (θ2) represent with angle, θ2The light path of Michelson interference filter time incident Difference.As long as have selected Integer n2After, simultaneous formula (3), (4) can solve θ2；
The angle of incidence of the regulation probe beam described in step 2, specific as follows:
2-1. before two-way probe beam regulates, by frequency harmony equipment manually by the 3rd light The output of electricity multiplier tube is adjusted to 0, i.e. allows Michelson interferometer filter initialize and is in frequency Rate lock-out state；
2-2. regulates the second spectroscope and the 3rd reflecting mirror so that the incidence angle θ of probe beam1With θ2The incidence angle θ that calculates with step 1 of angle1And θ2Consistent；
The most consistent determination methods is as follows:
When actual optical path adjusting, first disconnect difference amplifier and receive the feedback of frequency harmony equipment End, moves turntable by precision and first the incident angle of the most a branch of probe beam is adjusted to θ1, then The θ that the angle-determining of another bundle probe beam is calculated in theory2Near, then finely tune The accurate mobile turntable of two bundle probe beams, until the output of difference amplifier reaches 0；Two visit After the angular adjustment of pin light beam completes, then the feedback end of difference amplifier is accessed Michelson The frequency harmony equipment of interference filter；
Oscillograph is checked, it is judged that frequency-locked state described in step 3, specific as follows:
If Michelson interference filter is just locked in filters center frequency, then oscillograph Output signal be 0；If the impact of external environmental factor causes Michelson interferometer frequency Losing lock calmly, then understand output error signal and feed back to Michelson interference filter by difference amplifier The frequency harmony equipment of device, frequency harmony equipment adjusts dry under the driving of this error signal automatically The resonant frequency of interferometer, until locking onto required laser center frequency；In this process, show The output signal of ripple device also can progressively convergence 0.
The first described spectroscope is the spectroscope that reflectance is more than absorbance；Second spectroscope is The spectroscope of 50%:50% splitting ratio.
First described spectroscopical reflectance is as follows with absorbance ratio: T:R=10%:90%.
Beneficial effects of the present invention is as follows:
The present invention is suitable for the resonant frequency lock of various Michelson interference type spectral wave filter Fixed, it is achieved simple, can avoid traditional locks frequency method to circuit and the complicated requirement of light path, from And there is stronger system stability and robustness.
Accompanying drawing explanation
Fig. 1 is the index path of apparatus of the present invention；
Fig. 2 is the change of Michelson interference type spectral wave filter optical path difference and incidence in the present invention One example of angular dependence；
Fig. 3 is present invention when locking Michelson interference type spectral wave filter, difference amplifier The error signal of output and the quantitative relation curve of frequency losing lock.
In figure, laser instrument 1, collimator and extender device the 2, first spectroscope the 3, first reflecting mirror 4, Second reflecting mirror the 5, second spectroscope the 6, the 3rd reflecting mirror 7, cube Amici prism the 8, the 4th Reflecting mirror the 9, the 5th reflecting mirror 10, lens the 11, first photomultiplier tube (PMT) 12, Second photomultiplier tube the 13, the 3rd photomultiplier tube 14, difference amplifier 15, frequency harmony Equipment 16, oscillograph 17.
Detailed description of the invention
The invention will be further described below in conjunction with the accompanying drawings.
As it is shown in figure 1, a kind of Michelson interference type spectral filter resonant frequency locking dress Put, including laser instrument divided beam system a, Michelson interference-type filter system b and photoelectricity Detection system c；
Laser instrument divided beam system a include laser instrument 1, collimator and extender device the 2, first spectroscope 3, First reflecting mirror the 4, second reflecting mirror the 5, second spectroscope the 6, the 3rd reflecting mirror 7；Michelson Interference-type filter system b includes cube Amici prism the 8, the 4th reflecting mirror the 9, the 5th reflection Mirror 10.Wherein the 5th reflecting mirror 10 and frequency harmony equipment 16 are mechanically connected and realize resonance frequency Rate adjusts；Photodetection system c include lens the 11, first photomultiplier tube (PMT) 12, Second photomultiplier tube the 13, the 3rd photomultiplier tube 14, difference amplifier 15, oscillograph 17.
The collimated beam expander of laser beam 2 that laser instrument 1 is launched is expanded as angle pencil of ray parallel Light；Angle pencil of ray directional light is divided into two-way through the first spectroscope 3, and wherein a road is through first point It is emitted directly toward after light microscopic 3 transmission and treats that Michelson interference filter system b of frequency locking is as monitoring Light beam；After another road sequentially passes through first reflecting mirror the 4, second reflecting mirror 5, then through second point Light microscopic 6 is divided into two-way, and wherein the first via is after the second spectroscope 6 transmission, more anti-through the 3rd Penetrate mirror 7 to reflect with angle, θ2Enter the Michelson interference filter system b conduct treating frequency locking Probe beam；Second tunnel is direct with angle, θ after the second spectroscope 6 reflection1Enter and treat frequency locking Michelson interference filter system b is as probe beam.Two-way probe beam and monitoring Light beam through until Michelson interference filter system b of frequency locking, two-way probe beam with Monitoring light beam is divided into by cube Amici prism 8 in Michelson interference filter system b Two-way, a road is reflected back cube point by the 4th reflecting mirror 9 after cube Amici prism 8 transmission again Light prism 8, and it is reflected into lens 11 through cube Amici prism 8；Another road is through cube light splitting It is reflected back cube Amici prism 8, and warp cube by the 5th reflecting mirror 10 again after prism 8 reflection Amici prism 8 is transmitted into lens 11；Several roads light beam is focused on its focal plane not by lens 11 Co-located also interferes respectively, and interference signal respectively by the first photomultiplier tube 12, Two photomultiplier tube the 13, the 3rd photomultiplier tubes 14 are received and converted into the signal of telecommunication.By first The signal of telecommunication input difference amplifier 15 of photomultiplier tube the 12, second photomultiplier tube 13 output, The output signal of difference amplifier 15 feeds back to frequency harmony equipment 16；And the 3rd photomultiplier transit The output signal of telecommunication input oscillograph 17 of pipe 14 monitors signal as frequency-locked state.
A kind of Michelson interference type spectral filter resonant frequency locking means, specifically include as Lower step:
Step 1. builds Michelson interference type spectral filter resonance frequency locking device；
Step 2. calculates the angle of incidence of two bundle probe beams；
Step 3. regulates the angle of incidence of two bundle probe beams；
Step 4. checks oscillograph, it is judged that frequency-locked state.
Michelson interference type spectral filter resonance frequency locking device described in step 1 is i.e. For the device shown in Fig. 1；
The angle of incidence of the two-way probe beam described in step 2 includes θ1And θ2；θ1And θ2Need to meet Certain coupling requirement, specific as follows determines:
θ1Choose the probe beam needing to make Michelson interference filter incident to this angle Optical path difference and the difference Δ OPD (θ of optical path difference during 0 degree of angle incidence1) it is (n1+1/4)λ0, i.e.
ΔOPD(θ1)=(n1+1/4)λ0 (1)
Wherein, λ0It is laser center wavelength, n1It is that (recommendation is an integer to be selected 0～10)；ΔOPD(θ1) the structure of computational methods and Michelson interference filter used Relating to parameters；If the length that arm interfered by Michelson interference filter two is respectively d1And d2, Refractive index is respectively ρ1And ρ2, then Δ OPD (θ1) can calculate by following several formulas
OPD ( θ 1 ) = 2 · abs [ ρ 1 d 1 ( 1 - sin 2 θ 1 ρ 1 2 ) 1 / 2 - ρ 2 d 2 ( 1 - sin 2 θ 1 ρ 2 2 ) 1 / 2 ] - - - ( 2 a )
OPD (0)=2 abs (ρ1d1-ρ2d2) (2b)
ΔOPD(θ1)=abs [OPD (θ1)-OPD(0)] (2c)
Wherein, abs () expression takes absolute value, OPD (θ1) represent with angle, θ1Time incident The optical path difference of Michelson interference filter, Michelson when OPD (0) represents light normal incidence The optical path difference of interference filter；As long as have selected Integer n1After, simultaneous formula (1), (2) Solve θ1；
Want and θ1Match, incidence angle θ2It must is fulfilled for Michelson interference filter to this spy The change between optical path difference when the optical path difference of pin light beam and normal incidence:
ΔOPD(θ2)=(n2-1/4)λ0 (3)
In formula (3), n2For the integer that another is to be selected, it is 0～50 and than selected n1 Greatly, in like manner, Δ OPD (θ2) can calculate by following several formulas
OPD ( θ 2 ) = 2 · abs [ ρ 1 d 1 ( 1 - sin 2 θ 2 ρ 1 2 ) 1 / 2 - ρ 2 d 2 ( 1 - sin 2 θ 2 ρ 2 2 ) 1 / 2 ] - - - ( 4 a )
ΔOPD(θ2)=abs [OPD (θ2)-OPD(0)] (4b)
Wherein OPD (θ2) represent with angle, θ2The light path of Michelson interference filter time incident Difference.As long as have selected Integer n2After, simultaneous formula (3), (4) can solve θ2。
The angle of incidence of the regulation probe beam described in step 3, specific as follows:
3-1. is before two-way probe beam regulates, by frequency harmony equipment manually by the 3rd light The output of electricity multiplier tube 14 is adjusted to 0, i.e. allows Michelson interferometer filter initialize and is in Frequency locking state；
3-2. regulates the second spectroscope 6 and the 3rd reflecting mirror 7 so that the incidence angle θ of probe beam1 And θ2The incidence angle θ that calculates with step 2 of angle1And θ2Consistent.
The most consistent determination methods is as follows: when actual optical path adjusting, first disconnects difference and puts The feedback end of frequency harmony equipment 16 received by big device 15, moves turntable first by wherein one by precision The incident angle of bundle probe beam is adjusted to θ1, then the angle-determining of another bundle probe beam is existed The θ that Theoretical Calculation goes out2Near, the then accurate mobile turntable of fine setting the second bundle probe beam, Until the output of difference amplifier 15 reaches 0；After the angular adjustment of two probe beams completes, The feedback end of difference amplifier is accessed the frequency harmony equipment of Michelson interference filter again 16。
Oscillograph is checked, it is judged that frequency-locked state described in step 4, specific as follows:
If Michelson interference filter is just locked in filters center frequency, then oscillograph The output signal of 17 is 0；If the impact of the factors such as external environment condition causes Michelson interferometer Frequency losing lock calmly, then understand output error signal and feed back to Michelson interference by difference amplifier The frequency harmony equipment of wave filter, frequency harmony equipment is adjusted under the driving of this error signal automatically The resonant frequency of whole interferometer, until locking onto required laser center frequency.In this process, The output signal of oscillograph 17 also can progressively convergence 0.
The first described spectroscope 3 is the spectroscope that reflectance is much larger than absorbance, as T:R=10%:90%；Second spectroscope 6 is the spectroscope having 50%:50% splitting ratio.For Facilitating angle adjustment, the second spectroscope 6 and the 3rd reflecting mirror 7 can be placed on precise rotation On platform.
Embodiment
In Fig. 1, laser instrument 1 and laser radar emitter share by the way of light splitting, its frequency It it is exactly the reference frequency needing locking；
Above-mentioned collimator and extender device 2 can use common beam expander, such as Beijing company of Daheng GCO-141602 model beam expanding lens, 6 times expand；
Above-mentioned first spectroscope 3 uses the spectroscope of T:R=10%:90%, as Beijing Daheng is public The GCC-411215 of department；Second spectroscope 6 is with the spectroscope of common T:R=50%:50% i.e. Can, such as the GCC-411102 of Beijing company of Daheng；
Above-mentioned: first reflecting mirror the 4, second reflecting mirror the 5, the 3rd reflecting mirror 7 uses common anti- Penetrate mirror, such as the GCC-101102 of Beijing company of Daheng, diameter 25.4mm；
Lens 11 are long-focus lenss, such as Beijing company of Daheng GCL-010214, burnt Long 400mm;
First photomultiplier tube (PMT) the 12, second photomultiplier tube the 13, the 3rd photoelectricity times Increase pipe 14 and can use the R6358 model photomultiplier tube of Bin Song company of Japan；
Difference amplifier 15 can select chip I NA126 that Texas Instruments (TI) produces；
Oscillograph 17 uses common oscillograph, such as YB4320/20A/40.
Michelson interference filter can be homemade can also be buy integrating device. If homemade, its frequency harmony device 16 generally uses piezoelectric transducer PZT, as PI is public The PZ150E of department, cube Amici prism 8 is the common cube of Amici prism of 50%:50%, Such as Beijing company of Daheng GCC-401012, the 4th reflecting mirror the 9, the 5th reflecting mirror 10 is common anti- Penetrate mirror, such as the GCC-101102 of Beijing company of Daheng；If the integrated products bought, Frequency harmony device can be accompanied with.
Its frequency locker is further described below in conjunction with concrete Michelson interference filter parameter Fixed method.
Light path the most as shown in Figure 1 puts up device, then based on the method described in step 2 Calculate the angle of incidence of two probe beams.
Assume to treat that the Michelson interference filter two of frequency locking interferes the length of arm and the refractive index to be d1=87.578mm, d2=59.318mm, ρ1=1.4765, ρ2=1.00027.In order to enable by formula (1-4) incidence angle θ of two probe beams is determined1And θ2, in addition it is also necessary to arbitrarily selected two therein Integer n1And n2.Generally, this n1Can arbitrarily choose, it is recommended that value is 0～10, so can Ensure that the angle of incidence calculated is unlikely to the least, also can guarantee that Michelson interference filter pair The OPD change of the probe beam that this angle is incident is unlikely to the most greatly.Same, n2Choose The θ calculated should be ensured1And θ2Difference will not be the least, and Michelson to be ensured interferes filter The OPD of this probe beam is changed as far as possible in wavelength magnitude by ripple device, it is recommended that value be 0～50 and Less than selected n1。
A kind of auxiliary chooses n1And n2Method be to make this according to formula (2) or formula (4) The relation schematic diagram that Michelson interference filter angle of incidence changes with OPD, as shown in Figure 2. It can be observed from fig. 2 that this Michelson interference filter OPD changes also with angle of incidence Inconspicuous, therefore less n can be chosen1And n2.For example, it is possible to choose n1=0, n2=1, generation Enter formula (1-4) and θ can be solved1=4.024 °, θ2=5.086 °.
After being calculated the angle of incidence of two probe beams, then regulate two probe lights by step 3 The incident angle of bundle.The state of resonant frequency locking i.e. be can be observed by step 4.
In order to be able to illustrate that the feasibility of the program, Fig. 3 give error signal with frequency losing lock feelings The relation curve of condition.It will be seen that this technical scheme can detect the direction that frequency losing lock is fixed: When the resonant frequency of Michelson interference filter is more than filters center frequency, difference is put The error signal that big device output is positive, and when the resonant frequency of Michelson interference filter is less than During filters center frequency, the error signal that difference amplifier output is negative.System can be according to frequency Direction that losing lock is fixed and the symbol of size automatic alignment error signal and size are to drive Michelson interferometer frequency harmony equipment is towards being correctly oriented motion, so that interferometer weight Newly return to frequency locking state.And error signal variations is precipitous, show that there is the highest frequency locking Susceptiveness.

Claims (4)

1. a Michelson relates to type spectral filter resonant frequency locking device, it is characterised in that include laser instrument divided beam system, Michelson interference-type filter system and Photodetection system；
Laser instrument divided beam system includes laser instrument, collimator and extender device, the first spectroscope, the first reflecting mirror, the second reflecting mirror, the second spectroscope, the 3rd reflecting mirror；Michelson interference-type filter system includes a cube Amici prism, the 4th reflecting mirror, the 5th reflecting mirror, and wherein the 5th reflecting mirror and the connection of frequency harmony plant machinery realize resonant frequency adjustment；Photodetection system includes lens, the first photomultiplier tube, the second photomultiplier tube, the 3rd photomultiplier tube, difference amplifier, oscillograph；
The collimated beam-expanding system of laser beam that laser instrument is launched is expanded as angle pencil of ray directional light；Angle pencil of ray directional light is divided into two-way through the first spectroscope, and wherein a road is emitted directly toward the Michelson interference filter system treating frequency locking as monitoring light beam after the first spectroscope transmission；After another road sequentially passes through the first reflecting mirror, the second reflecting mirror, then being divided into two-way through the second spectroscope, wherein the first via is after the second spectroscope transmission, then reflects through the 3rd reflecting mirror with angle, θ2Enter and treat that the Michelson interference filter system of frequency locking is as probe beam；Second tunnel is direct with angle, θ after the second dichroic mirror1Enter and treat that the Michelson interference filter system of frequency locking is as probe beam；Two-way probe beam and monitoring light beam are through the Michelson interference filter system until frequency locking, two-way probe beam is divided into two-way with monitoring light beam by intrasystem cube of Amici prism of Michelson interference filter, one tunnel is reflected back a cube Amici prism by the 4th reflecting mirror after cube Amici prism transmission again, and is reflected into lens through a cube Amici prism；Another road is reflected back a cube Amici prism by the 5th reflecting mirror after cube Amici prism reflection again, and is transmitted into lens through a cube Amici prism；Several roads light beam and is interfered at its focal plane diverse location respectively by lens focus, and interference signal is received and converted into the signal of telecommunication by the first photomultiplier tube, the second photomultiplier tube, the 3rd photomultiplier tube respectively；By the first photomultiplier tube, the signal of telecommunication input difference amplifier of the second photomultiplier tube output, the output signal of difference amplifier feeds back to frequency harmony equipment；And the output signal of telecommunication input oscillograph of the 3rd photomultiplier tube monitors signal as frequency-locked state.
2. the method using a kind of Michelson interference type spectral filter resonant frequency locking device as claimed in claim 1, it is characterised in that comprise the steps:
Step 1. calculates the angle of incidence of two bundle probe beams；
Step 2. regulates the angle of incidence of two bundle probe beams；
Step 3. checks oscillograph, it is judged that frequency-locked state；
The angle of incidence of the two-way probe beam described in step 1 includes θ1And θ2；θ1And θ2Need to meet and mate requirement as follows:
θ1The optical path difference choosing the probe beam needing to make Michelson interference filter incident to this angle and the difference △ OPD (θ of optical path difference during 0 degree of angle incidence1) it is (n1+1/4)λ0, i.e.
△OPD(θ1)=(n1+1/4)λ0 (1)
Wherein, λ0It is laser center wavelength, n1Being an integer to be selected, span is 0～10；△OPD(θ1) computational methods relevant with the structural parameters of Michelson interference filter used；If the length that arm interfered by Michelson interference filter two is respectively d1And d2, refractive index is respectively ρ1And ρ2, then △ OPD (θ1) can calculate by following several formulas
OPD (0)=2 abs (ρ1d1-ρ2d2) (2b)
△OPD(θ1)=abs [OPD (θ1)-OPD(0)] (2c)
Wherein, abs () expression takes absolute value, OPD (θ1) represent with angle, θ1The optical path difference of Michelson interference filter time incident, the optical path difference of Michelson interference filter when OPD (0) represents light normal incidence；As long as have selected Integer n1After, simultaneous formula (1), (2) can solve θ1；
Want and θ1Match, incidence angle θ2It must is fulfilled for Michelson interference filter to the change between the optical path difference when optical path difference of this probe beam and normal incidence:
△OPD(θ2)=(n2-1/4)λ0 (3)
In formula (3), n2For the integer that another is to be selected, it is 0～50 and than selected n1Greatly, in like manner, △ OPD (θ2) can calculate by following several formulas
△OPD(θ2)=abs [OPD (θ2)-OPD(0)] (4b)
Wherein OPD (θ2) represent with angle, θ2The optical path difference of Michelson interference filter time incident；As long as have selected Integer n2After, simultaneous formula (3), (4) can solve θ2；
The angle of incidence of the regulation probe beam described in step 2, specific as follows:
The output of the 3rd photomultiplier tube, before two-way probe beam regulates, is manually adjusted to 0 by frequency harmony equipment by 2-1., i.e. allows Michelson interferometer filter initialize and is in frequency locking state；
2-2. regulates the second spectroscope and the 3rd reflecting mirror so that the incidence angle θ of probe beam1And θ2The incidence angle θ that calculates with step 1 of angle1And θ2Consistent；
The most consistent determination methods is as follows:
When actual optical path adjusting, first disconnect difference amplifier and receive the feedback end of frequency harmony equipment, move turntable by precision and first the incident angle of the most a branch of probe beam is adjusted to θ1, then the θ that the angle-determining of another bundle probe beam is calculated in theory2Near, the then accurate mobile turntable of fine setting the second bundle probe beam, until the output of difference amplifier reaches 0；After the angular adjustment of two probe beams completes, then the feedback end of difference amplifier is accessed the frequency harmony equipment of Michelson interference filter；
Oscillograph is checked, it is judged that frequency-locked state described in step 3, specific as follows:
If Michelson interference filter is just locked in filters center frequency, the most oscillographic output signal is 0；If the impact of external environmental factor causes Michelson interferometer frequency losing lock fixed, then difference amplifier is understood output error signal and feeds back to the frequency harmony equipment of Michelson interference filter, frequency harmony equipment adjusts the resonant frequency of interferometer under the driving of this error signal automatically, until locking onto required laser center frequency；In this process, oscillographic output signal also can progressively convergence 0.
The method of a kind of Michelson interference type spectral filter resonant frequency the most as claimed in claim 2 locking, it is characterised in that the first described spectroscope is the spectroscope that reflectance is more than absorbance；Second spectroscope is the spectroscope of 50%:50% splitting ratio.
The method of a kind of Michelson interference type spectral filter resonant frequency the most as claimed in claim 3 locking, it is characterised in that first described spectroscopical reflectance is as follows with absorbance ratio: T:R=10%:90%.
CN201410025286.9A 2014-01-20 2014-01-20 A kind of Michelson interference type spectral filter resonant frequency locking device and method Active CN103809166B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410025286.9A CN103809166B (en) 2014-01-20 2014-01-20 A kind of Michelson interference type spectral filter resonant frequency locking device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410025286.9A CN103809166B (en) 2014-01-20 2014-01-20 A kind of Michelson interference type spectral filter resonant frequency locking device and method

Publications (2)

Publication Number Publication Date
CN103809166A CN103809166A (en) 2014-05-21
CN103809166B true CN103809166B (en) 2016-08-17

Family

ID=50706218

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410025286.9A Active CN103809166B (en) 2014-01-20 2014-01-20 A kind of Michelson interference type spectral filter resonant frequency locking device and method

Country Status (1)

Country Link
CN (1) CN103809166B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105486664B (en) * 2015-12-31 2018-04-20 浙江大学 Detect marine phytoplankton biomass and the laser radar apparatus and method of POC
CN105891801B (en) * 2016-04-07 2018-04-20 浙江大学 Multiple-harmonic heterodyne locks the device of field widening Michelson's interferometer
GB2551968A (en) * 2016-06-28 2018-01-10 Oclaro Tech Ltd Optical locker
CN106443698A (en) * 2016-10-27 2017-02-22 青岛科技大学 A device for adjusting the double beam interference intersection position of a solid laser velocimeter
CN110515154B (en) * 2019-08-19 2020-10-20 中国科学院大学 Optical switch control method based on photonic crystal field resonance mode and optical switch

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101299075A (en) * 2008-05-30 2008-11-05 福州高意通讯有限公司 Adjustable optical filter optical structure and spectrum analyzer with the same
CN103308926A (en) * 2013-06-18 2013-09-18 浙江大学 Laser radar set with high spectral resolution

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007055665A1 (en) * 2007-11-21 2009-05-28 Dr. Johannes Heidenhain Gmbh Interferometer arrangement and method for their operation

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101299075A (en) * 2008-05-30 2008-11-05 福州高意通讯有限公司 Adjustable optical filter optical structure and spectrum analyzer with the same
CN103308926A (en) * 2013-06-18 2013-09-18 浙江大学 Laser radar set with high spectral resolution

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
高频锁相激光干涉仪技术纳米定位系统;Luc Chassagne et al.;《中国计量学院学报》;20060630;第17卷(第2期);第91-94页 *

Also Published As

Publication number Publication date
CN103809166A (en) 2014-05-21

Similar Documents

Publication Publication Date Title
CN102538775B (en) Cold atom beam interference gyro device
CN103809166B (en) A kind of Michelson interference type spectral filter resonant frequency locking device and method
CN103809167B (en) A kind of FP interference type spectral filter resonance frequency locking device and method
CN104316186B (en) A kind of spectral measurement method of optically-based frequency comb
CN108181627B (en) All-fiber bidirectional mode-locking femtosecond laser ranging device and method based on time domain scanning
CN102576971A (en) Optical signal processing with modelocked lasers
CN101907513B (en) Diffraction property low-light test system and method of acousto-optic tunable filter (AOTF)
WO2016154780A1 (en) Laser interference wavelength lever-type absolute distance measurement apparatus and method
KR102453813B1 (en) Light comb generating device and spectrometers comprising the same
US20110235046A1 (en) Imaging apparatus
CN102679907B (en) High-precision differential interference measuring system and method based on LED light source
CN106289499A (en) A kind of micrometer vibrational system utilizing femtosecond laser and micrometer method for oscillating
CN108107008B (en) Time domain heat reflection spectrum measuring system
CN105988261B (en) A kind of vortex light field generation device
CN103308926A (en) Laser radar set with high spectral resolution
CN105005051A (en) Single-optical-path laser distance measuring system
CN103825193B (en) The ultra-narrow band excited state faraday anomalous dispersion atom filter method of communication band
CN110161528A (en) A kind of scene of fire complex environment laser three-dimensional imaging method based on optical coherence tomography
CN106932107A (en) A kind of topological charge measurement apparatus based on far field construction principle
Meiners-Hagen et al. Air index compensated interferometer as a prospective novel primary standard for baseline calibrations
CN112824930B (en) Microwave laser bidirectional coherent conversion device based on Redberg atoms
CN114899702A (en) Laser device offset frequency stabilizing device and method based on optical fiber ring resonator
CN105181155A (en) Terahertz pulse single-time detection system and detection method based on single-mode fiber
CN103075966A (en) Displacement measuring system
CN104184037A (en) Fully-polarization-maintaining active tracking type optical fiber and optical comb light source

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