CN112180394A - Multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system - Google Patents
Multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system Download PDFInfo
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- G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
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- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
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- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
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- 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
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
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Abstract
The invention discloses a multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system, which comprises a multi-longitudinal-mode laser, a half-wave plate, a polarization splitting prism, an acousto-optic modulation module, a spectrum frequency discrimination interferometer, a converging lens, a photoelectric detector, a peak holding circuit and a proportional-integral-differential servo control module, wherein the multi-longitudinal-mode laser is connected with the half-wave plate through the acousto-optic modulation module; after multi-longitudinal mode pulse laser output by the multi-longitudinal mode laser passes through a half-wave plate and a polarization beam splitting prism, low-power light beams are obtained through beam splitting; the low-power light speed is subjected to frequency shift by the acousto-optic modulation module and then enters the spectral discrimination interferometer, and the emergent light is received by the photoelectric detector after passing through the converging lens; the electric signal output by the photoelectric detector is transmitted to the peak holding circuit for processing, then the output signal is transmitted to the proportional-integral-derivative servo control module, and the output tuning voltage acts on the spectrum frequency discrimination interferometer to realize the resonance frequency locking. The invention can meet the requirement of multi-longitudinal mode HSRL on the frequency stability of the spectrum frequency discrimination interferometer.
Description
Technical Field
The invention belongs to the technical field of atmospheric laser radars, and particularly relates to a multi-longitudinal-mode high spectral resolution laser radar interferometer frequency locking system based on a peak holding circuit.
Background
The High Spectral Resolution Lidar (HSRL) is one of the most accurate atmospheric aerosol detection systems at present, and has the advantages that an optical filter with High Spectral Resolution is used for separating atmospheric aerosol millimeter scattering signals and atmospheric molecular rayleigh scattering signals in atmospheric backscattering signals, and then the characteristics of the backscattering coefficient, the extinction coefficient and the like of the aerosol are accurately inverted.
In view of the poor environmental adaptability and the large size of the single longitudinal mode laser used in the current HSRL, research on a new HSRL system using multiple longitudinal mode lasers is under way. The principle of the multi-longitudinal-mode HSRL is substantially the same as that of the HSRL, namely, the atmospheric backscattered signal of each longitudinal-mode component is spectrally discriminated by an interferometric discriminator with a periodically distributed transmittance curve.
The premise of the above implementation is to ensure that the frequency of each laser longitudinal mode and the relative position of the frequency discriminator characteristic curve are stable, so that the frequency locking processing needs to be performed on the interferometer, and the frequency discrimination curve distribution of the interferometer moves along with the longitudinal mode to lock the two.
The frequency stability of the current interferometer discriminator adopted by the HSRL, such as a field-widening Michelson interferometer, a Fabry-Perot interferometer and the like, is slightly poor, and the frequency stability is mainly kept by adopting a temperature control method. Although the method can realize the long-term stability of the frequency, the temperature regulation mode with the slow response speed has poor short-term stability and extremely high requirement on temperature precision, so a new frequency locking mode is required to be involved so as to enable the atmospheric echo signals of all the longitudinal modes to be strictly matched with the frequency discrimination curve of the device. The multi-longitudinal mode laser in the multi-longitudinal mode HSRL has a simple structure, and directly outputs pulse laser from the resonant cavity, so that the conventional continuous laser frequency locking mode is not applicable to the system.
Disclosure of Invention
The invention provides a frequency locking system of a multi-longitudinal-mode high-spectral-resolution laser radar interferometer, which improves the spectrum frequency discrimination quality of the multi-longitudinal-mode high-spectral-resolution laser radar during atmospheric detection and solves the control difficulty caused by the characteristic that a multi-longitudinal-mode laser directly outputs pulsed light.
A frequency locking system of a multi-longitudinal-mode high-spectral-resolution laser radar interferometer comprises a multi-longitudinal-mode laser, a half-wave plate, a polarization beam splitter prism, an acousto-optic modulation module, a spectrum frequency discrimination interferometer, a converging lens, a photoelectric detector, a peak holding circuit and a proportional-integral-differential servo control module;
the multi-longitudinal-mode pulse laser output by the multi-longitudinal-mode laser is subjected to polarization state adjustment by a half-wave plate and then is split into a high-power light beam and a low-power light beam by a polarization splitting prism, the high-power light beam is used as a laser radar detection signal, and the low-power light beam is used for frequency locking of a spectrum frequency discrimination interferometer;
the low-power light speed is subjected to frequency shift by the acousto-optic modulation module and then is incident to the spectral discrimination interferometer needing to be locked, and light emitted from the spectral discrimination interferometer is received by the photoelectric detector after passing through the converging lens;
the electric signal output by the photoelectric detector is transmitted to the peak holding circuit for processing, then the peak holding signal and the sampling trigger signal are output to the proportional-integral-derivative servo control module, and the proportional-integral-derivative servo control module outputs tuning voltage to act on the spectrum frequency discrimination interferometer to realize resonance frequency locking.
Preferably, the acousto-optic modulation module is of a two-stage modulation structure and comprises a primary acousto-optic modulator and a secondary acousto-optic modulator; the primary acousto-optic modulator is used for performing frequency shift processing on a low-power light beam obtained by splitting the output of the multi-longitudinal-mode laser; the secondary acousto-optic modulator is used for further frequency shifting the pulse light which is subjected to frequency shifting. On the premise that a laser is matched with a mode, two-stage frequency shift enables a series of laser longitudinal modes to be in a dynamic range of a frequency discrimination curve of a spectrum frequency discrimination interferometer.
Furthermore, the peak holding circuit comprises a primary peak holding circuit and a secondary peak holding circuit, wherein the primary peak holding circuit comprises a transconductance amplifier, a discriminator diode-holding capacitor circuit and a voltage buffer circuit; the two-stage peak holding circuit comprises a voltage amplifying circuit, a discriminating diode-holding capacitor circuit, a voltage comparator, a monostable trigger circuit, a peak holding switch circuit and a voltage buffer circuit.
Because the pulse width of the laser in the system is in ns magnitude and the interval between every two pulses is long, a two-stage peak holding structure is adopted.
The primary peak holding circuit is used for realizing a short-time peak holding function and widening narrow pulses into wide pulses.
The second-stage peak holding circuit is used for further holding the long-time peak value of the wide pulse output by the first-stage peak holding circuit, and generating a threshold signal with fixed time when each pulse arrives, so that the holding capacitor is automatically discharged at a set time to realize fixed peak holding time, and in addition, a trigger signal is generated to be used in the AD acquisition process of the proportional-integral-differential servo control module.
The first-stage peak holding circuit is used for primary peak holding, the capacitance value of the adopted capacitor is small, internal charges leak light in a short time, and the output holding signal is characterized by a pulse signal with longer falling time and wider pulse width compared with the original pulse.
The secondary peak holding circuit carries out peak holding on the widened pulse in the true sense, and utilizes the functions of diode on-off and capacitor charging to retain the pulse peak voltage, and utilizes the voltage comparator and the monostable trigger to generate a path of peak holding threshold signal with fixed time, so as to control the switch circuit to release the charge in the holding capacitor after the threshold signal is finished, thereby preparing for carrying out peak holding on the next pulse.
The proportional-integral-differential servo control module receives a peak holding signal and a sampling trigger signal, collects peak holding voltage within holding time and performs time domain averaging, obtains a calculated result voltage value after proportional-integral-differential operation, outputs continuous tuning voltage after level conversion and amplification are performed by a peripheral circuit, and acts on a piezoelectric ceramic module of the spectrum frequency discrimination interferometer to realize feedback control of the resonant frequency.
The proportional-integral-derivative servo module collects each held voltage value for multiple times under the triggering of the rising edge of the output signal of the voltage comparator in the secondary peak holding circuit and averages the voltage values to improve the precision. Because the pulse light is detected after passing through the interferometer frequency discriminator, the peak amplitude of the pulse light corresponds to the relative position of each longitudinal mode and the frequency discrimination curve of the interferometer. When the longitudinal modes of radar detection signals are all located at the resonance point of the interferometer, the longitudinal modes of the frequency-locked light passing through the acousto-optic frequency shift are all located at the edge of an interference curve, and therefore the voltage value acquired by the module is related to the frequency offset of the interferometer relative to the laser. Accordingly, the proportional-integral-derivative operation is performed on the voltage values of a series of pulses to obtain corresponding continuous output voltages for control. The voltage is subjected to level shift and appropriate amplification through a peripheral amplification circuit to obtain a tuning voltage which enables the frequency of the interferometer to follow the laser, so that each longitudinal mode is aligned with each resonance point of the interferometer to ensure that a Mi scattering signal in an atmosphere echo signal is accurately filtered.
The spectrum frequency discrimination interferometer is provided with a piezoelectric ceramic module, the piezoelectric ceramic module is used for controlling the frequency of the interferometer according to tuning voltage, and comprises a piezoelectric ceramic driver and a piezoelectric ceramic displacement table; the piezoelectric ceramic driver is used for amplifying the power of the tuning voltage, and the piezoelectric ceramic displacement platform is used for controlling the interference arm length of the interferometer frequency discriminator.
Compared with the prior art, the invention has the following beneficial effects:
1. the system solves the problem that the traditional laser frequency locking method is not suitable for the condition of a pulse laser light source, and can meet the requirement of multi-longitudinal-mode HSRL on the frequency stability of the spectrum frequency discrimination interferometer in a corresponding wave band.
2. The system has the advantages of simple equipment, low cost and low requirement on the external environment, and accords with the characteristics of low cost and integration of a multi-longitudinal-mode HSRL system.
3. The system can be applied to other fields with high requirements on the frequency stability of the interference instrument, such as the field of interference detection.
Drawings
FIG. 1 is a schematic diagram of an apparatus of a multi-longitudinal-mode high spectral resolution laser radar interferometer frequency locking system according to the present invention;
FIG. 2 is a schematic diagram of a peak hold circuit of the present invention;
FIG. 3 is a signal processing flow diagram of the PID servo module of the present invention.
Detailed Description
The invention will be described in further detail below with reference to the drawings and examples, which are intended to facilitate the understanding of the invention without limiting it in any way.
As shown in fig. 1, a frequency locking system for a multi-longitudinal-mode high-spectral-resolution lidar interferometer comprises a multi-longitudinal-mode laser 1, a half-wave plate 2, a polarization splitting prism 3, an acousto-optic modulation module 4, a spectrum frequency discrimination interferometer 5, a converging lens 6, a photoelectric detector 7, a peak holding circuit 8 and a proportional-integral-differential servo control module 9.
The laser output by the multi-longitudinal mode laser 1 is firstly polarized by a half-wave plate 2, and then a beam of light is split by a polarization beam splitter prism 3 and enters an acousto-optic modulation module 4. The frequency-locked light is subjected to frequency shift by the acousto-optic modulation module 4 and then enters the spectral discrimination interferometer 5, and the light emitted from the spectral discrimination interferometer passes through the converging lens 6 and is received by the photoelectric detector 7. The output electrical signal is firstly processed by the peak holding circuit 8, and the obtained trigger signal and the pulse signal after the peak holding are transmitted to the proportional-integral-derivative servo control module 9, so that a control voltage for enabling the interferometer frequency to follow the laser frequency is generated and acts on the piezoelectric ceramic module of the spectrum frequency discrimination interferometer 5.
Because each longitudinal mode frequency output by the acousto-optic modulation module 4 is integrally moved relative to the output of the laser, when each longitudinal mode frequency output by the laser is positioned at the resonance point of the frequency discrimination curve of the interferometer, the longitudinal mode of the frequency-locked light is integrally positioned at the edge of the frequency discrimination curve. The amplitude of the frequency-locked light output from the interferometer can thus be indicative of the degree of frequency shift of the respective longitudinal mode before the frequency shift relative to the resonance point of the interferometer.
The photodetector 7 receives the frequency-locked light and outputs a narrow pulse signal. Because the pulse width of the pulse signal is extremely narrow, the repetition frequency is low, the typical values are 10ns and 10Hz, and the peak voltage of the pulse signal is difficult to accurately measure by normal AD sampling, the narrow pulse is processed into a rectangular signal by adopting a peak holding circuit 8, and the proportional-integral-differential servo control module 9 can accurately collect the pulse peak value. In addition, the holding voltage is difficult to stabilize for a long time when the pulse width is extremely narrow, and since the charge leakage of the capacitor is in a descending trend, the descending speed is not constant in relation to the pulse amplitude, and the final frequency locking effect is greatly influenced, the peak holding circuit 8 here is composed of a primary peak holding part and a secondary peak holding part.
As shown in fig. 2, in the first-stage peak-hold, firstly, a transconductance amplifier a1 is used to convert the pulse voltage output by the detector into a pulse current and amplify the pulse current, the forward direction of the pulse charges a holding capacitor a3 through a diode a2, the capacitor charge cannot be quickly released due to the reverse turn-off of the diode, so that the pulse peak-hold phenomenon occurs, and the capacitor voltage finally passes through a voltage buffer a4 to realize buffered output. The capacitance value of the capacitor used by the first-stage peak holding circuit is small, the internal charge leakage phenomenon is serious, and therefore the holding voltage can quickly drop to zero. Therefore, the output of the primary peak holding circuit can be regarded as a pulse signal with a wider pulse width than the original pulse, and the secondary peak holding circuit is used for carrying out peak holding on the pulse signal in the true sense.
The wide pulse signal is firstly amplified by an operational amplifier a5 and then divided into two paths, one path of the wide pulse signal carries out peak value holding by using a diode a6 and a holding capacitor a7 with a larger capacitance value, and a discharge channel controlled by a field effect transistor a8 is arranged for the capacitor; the other input voltage comparator a9 generates a synchronous logic voltage pulse signal, the upper edge triggers a monostable trigger a10 to output a low level threshold signal with fixed time to the grid of the field effect transistor of the switch circuit to turn off, the field effect transistor is turned on after the threshold time is over, the charge in the holding capacitor is rapidly released to end the peak holding, and the next pulse is ready to be processed. The final peak hold signal is finally output through the voltage buffer a 11.
The signal processing flow of the proportional-integral-derivative servo module is shown in fig. 3. The proportional-integral-derivative servo module 9 receives the output signal of the voltage comparator a9 in the peak hold circuit 8 and the resulting peak hold signal. Each held voltage value is collected a plurality of times and averaged to improve accuracy under the trigger of the rising edge of the comparator output. The module performs proportional-integral-derivative operation on the voltage values of a series of pulses to obtain corresponding continuous output voltage for control. The voltage is subjected to level shift and proper amplification through a peripheral amplification circuit to obtain tuning voltage acting on the piezoelectric ceramic of the spectrum frequency discrimination interferometer, so that each longitudinal mode is aligned with each resonance point of the interferometer to ensure that a rice scattering signal in an atmosphere echo signal is accurately filtered.
The interferometer frequency locking system receives the pulse light transmitted through the interferometer and serializes the signal, so that feedback control is performed, and finally the resonance frequency of the interferometer is locked to each longitudinal mode frequency of the laser, frequency drift caused by environmental temperature and the like can be automatically compensated, the system locking precision is high, the locking process is intelligent and rapid, meanwhile, the cost is low, fundamental guarantee is created for high and stable operation of the interferometer spectral filter in the multi-longitudinal mode HSRL, and great promotion effect is achieved for improving the accuracy of HSRL atmospheric detection. In addition, the invention can also be used for carrying out frequency locking on pulse lasers for other purposes.
In this embodiment, the output wavelength of the multi-longitudinal mode laser 1 is 1064nm, and the pulse frequency is 10 Hz; the two-stage acousto-optic modulator adopts 200MHz drive to realize 400MHz frequency shift. The spectrum frequency discrimination interferometer 5 adopts a field-widening Michelson interferometer, and the dynamic range of the spectrum frequency discrimination interferometer can reach 1 GHz. The photoelectric detector 7 in the system selects an indium gallium arsenic photoelectric detector;
the transconductance amplifier a1 in the primary peak holding circuit adopts MAX435 chip, diode a2 adopts Schottky diode BAT17, and the operational amplifier a4 for buffering output adopts OP 07.
A pre-amplifier in the two-stage peak holding circuit adopts a broadband amplifier OPA646P, a diode a6 also adopts a Schottky diode BAT17, a voltage comparator a9 adopts a high-speed differential amplifier LM361, a monostable trigger a10 adopts 74HC123, a field effect transistor a8 adopts an N-channel enhancement type field effect transistor 2N7000, and a voltage buffer a11 adopts BUF 601.
The proportional-integral-derivative servo module 9 is mainly composed of an STM32F103RCT6 singlechip and peripheral circuits. STM32F103RCT6 has AD/DA resolution of 12 bits and voltage input/output range of 0-3.3V, and peripheral circuit adopts two operational amplifier LM358 to carry out the amplification and voltage following to singlechip output.
In the spectral discriminator interferometer 5, the piezoelectric ceramic driver may be an E00 system from Coremorrow, and the displacement stage of the interference arm mirror may be an XP-620 module from Coremorrow.
The embodiments described above are intended to illustrate the technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, additions and equivalents made within the scope of the principles of the present invention should be included in the scope of the present invention.
Claims (6)
1. A multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system is characterized by comprising a multi-longitudinal-mode laser, a half-wave plate, a polarization splitting prism, an acousto-optic modulation module, a spectrum frequency discrimination interferometer, a converging lens, a photoelectric detector, a peak holding circuit and a proportional-integral-differential servo control module;
the multi-longitudinal-mode pulse laser output by the multi-longitudinal-mode laser is subjected to polarization state adjustment by a half-wave plate and then is split into a high-power light beam and a low-power light beam by a polarization splitting prism, the high-power light beam is used as a laser radar detection signal, and the low-power light beam is used for frequency locking of a spectrum frequency discrimination interferometer;
the low-power light speed is subjected to frequency shift by the acousto-optic modulation module and then is incident to the spectral discrimination interferometer needing to be locked, and light emitted from the spectral discrimination interferometer is received by the photoelectric detector after passing through the converging lens;
the electric signal output by the photoelectric detector is transmitted to the peak holding circuit for processing, then the peak holding signal and the sampling trigger signal are output to the proportional-integral-derivative servo control module, and the proportional-integral-derivative servo control module outputs tuning voltage to act on the spectrum frequency discrimination interferometer to realize resonance frequency locking.
2. The multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system of claim 1, wherein the acousto-optic modulation module is of a two-stage modulation structure and comprises a primary acousto-optic modulator and a secondary acousto-optic modulator; the primary acousto-optic modulator is used for performing frequency shift processing on a low-power light beam obtained by splitting the output of the multi-longitudinal-mode laser; the secondary acousto-optic modulator is used for further frequency shifting the pulse light which is subjected to frequency shifting.
3. The multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system according to claim 1, wherein the peak holding circuit comprises a primary peak holding circuit and a secondary peak holding circuit, and the primary peak holding circuit comprises a transconductance amplifier, a discriminator diode-holding capacitor circuit and a voltage buffer circuit; the two-stage peak holding circuit comprises a voltage amplifying circuit, a discriminating diode-holding capacitor circuit, a voltage comparator, a monostable trigger circuit, a peak holding switch circuit and a voltage buffer circuit.
4. The multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system of claim 3, wherein the primary peak holding circuit is configured to implement a short-time peak holding function to widen a narrow pulse to a wide pulse;
the second-stage peak holding circuit is used for further holding the long-time peak value of the wide pulse output by the first-stage peak holding circuit, and generating a threshold signal with fixed time when each pulse arrives, so that the holding capacitor is automatically discharged at a set time to realize fixed peak holding time, and in addition, a trigger signal is generated to be used in the AD acquisition process of the proportional-integral-differential servo control module.
5. The multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system of claim 1, wherein the proportional-integral-differential servo control module receives a peak hold signal and a sampling trigger signal, collects a peak hold voltage within a hold time and performs time domain averaging, obtains a calculated result voltage value through proportional-integral-differential operation, performs level conversion and amplification through a peripheral circuit, outputs continuous tuning voltage, and acts on a piezoelectric ceramic module of a spectrum frequency discrimination interferometer to realize feedback control of a resonant frequency.
6. The multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system according to claim 1, wherein the spectrum frequency discrimination interferometer is provided with a piezoelectric ceramic module, the piezoelectric ceramic module is used for controlling the frequency of the interferometer according to tuning voltage, and comprises a piezoelectric ceramic driver and a piezoelectric ceramic displacement table; the piezoelectric ceramic driver is used for amplifying the power of the tuning voltage, and the piezoelectric ceramic displacement platform is used for controlling the interference arm length of the interferometer frequency discriminator.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010909864.0A CN112180394B (en) | 2020-09-02 | 2020-09-02 | Multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010909864.0A CN112180394B (en) | 2020-09-02 | 2020-09-02 | Multi-longitudinal-mode high-spectral-resolution laser radar interferometer frequency locking system |
Publications (2)
| Publication Number | Publication Date |
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| CN112180394A true CN112180394A (en) | 2021-01-05 |
| CN112180394B CN112180394B (en) | 2023-11-03 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103368053A (en) * | 2013-07-30 | 2013-10-23 | 哈尔滨工业大学 | LD (Laser Diode) pumping single frequency pulse 1645nm solid laser |
| CN106019312A (en) * | 2016-08-04 | 2016-10-12 | 浙江大学 | Multi-longitudinal-mode high-spectral-resolution lidar based on interference spectrum frequency detector |
| CN106019259A (en) * | 2016-07-11 | 2016-10-12 | 中国科学院上海技术物理研究所 | Laser frequency discriminating device and frequency discrimination method based on Mach-Zehnder interferometer |
| CN109378681A (en) * | 2018-11-08 | 2019-02-22 | 中国人民解放军国防科技大学 | Cascade frequency shift-based high-average-power mode-locked laser generation system and method |
| CN109556591A (en) * | 2018-11-22 | 2019-04-02 | 华中科技大学 | A kind of passive type lasergyro based on super stabilized laser |
-
2020
- 2020-09-02 CN CN202010909864.0A patent/CN112180394B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103368053A (en) * | 2013-07-30 | 2013-10-23 | 哈尔滨工业大学 | LD (Laser Diode) pumping single frequency pulse 1645nm solid laser |
| CN106019259A (en) * | 2016-07-11 | 2016-10-12 | 中国科学院上海技术物理研究所 | Laser frequency discriminating device and frequency discrimination method based on Mach-Zehnder interferometer |
| CN106019312A (en) * | 2016-08-04 | 2016-10-12 | 浙江大学 | Multi-longitudinal-mode high-spectral-resolution lidar based on interference spectrum frequency detector |
| CN109378681A (en) * | 2018-11-08 | 2019-02-22 | 中国人民解放军国防科技大学 | Cascade frequency shift-based high-average-power mode-locked laser generation system and method |
| CN109556591A (en) * | 2018-11-22 | 2019-04-02 | 华中科技大学 | A kind of passive type lasergyro based on super stabilized laser |
Non-Patent Citations (2)
| Title |
|---|
| 成中涛 等: "多纵模高光谱分辨率激光雷达研究", 《光学学报》 * |
| 王彬宇 等: "基于法布里－珀罗干涉仪的激光谱线特性测量研究", 《物理实验》 * |
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