CN105911534B - The optical filtering apparatus that transmitance changes with field of view of receiver angle - Google Patents
The optical filtering apparatus that transmitance changes with field of view of receiver angle Download PDFInfo
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- CN105911534B CN105911534B CN201610223507.2A CN201610223507A CN105911534B CN 105911534 B CN105911534 B CN 105911534B CN 201610223507 A CN201610223507 A CN 201610223507A CN 105911534 B CN105911534 B CN 105911534B
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- insulation cover
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- light
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- 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
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/0147—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on thermo-optic effects
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
A kind of optical filtering apparatus that transmitance changes with field of view of receiver angle, including receiving main lens, along the reception main lens optical axis and return laser beam direction be successively field stop, collimation lens, the front window glass of insulation cover, interferometric filter, insulation cover rear hatch glass and condenser lens, the field stop is located at the reception main lens focal plane, semiconductor cooler and thermistor are mounted on the insulation cover, and the plane of the front window glass, interferometric filter and rear hatch glass is parallel to each other.The present invention matches the central wavelength of certain angle illuminating coherent optical filter with light is received, at guarantee edge on the basis of big visual field transmitance, it realizes the decaying for receiving light to center small field of view, the dynamic range that laser radar system detects in the strong scattering mediums such as water, mist can be effectively improved.
Description
Technical field
The present invention relates to optically filtering, the optical filtering apparatus that especially a kind of transmitance changes with field of view of receiver angle should
Device is realized the decaying for receiving light to center small field of view, be can effectively improve on the basis of the big visual field transmitance in guarantee edge
The dynamic range that laser radar system detects in the strong scattering mediums such as water, mist.
Background technique
Laser radar carries out target acquisition in the strong scattering mediums such as water, mist, decays by force as caused by strong scattering medium,
The range attenuation of target echo signal seriously much than the decaying in normal atmospheric, therefore, can be to the detection of laser radar
Dynamic range put forward higher requirements.Currently used improving laser radar detects the side of dynamic range in strong scattering medium
Formula mainly has fixed proportion subchannel technology, logarithmic amplification technology, polarization technology, gate and synchronous variable-gain technology.
Fixed proportion subchannel technology is that the light splitting piece of fixed proportion is installed on receiving light path, is divided few channel and is used for
Closely strong echo-signal measurement, realizes the optical attenuation to closely strong echo-signal, is divided more channels for remote weak
Echo-signal measurement, guarantees the light transmission rate to remote weak echo signal.This is technically simple, mature, although can extend sharp
The dynamic range of optical radar, but be divided more channels and still will receive closely strong echo-signal and cause to be saturated, certain journey
The channel detector is influenced on degree to the detectivity and stability of remote weak echo signal.
Logarithmic amplification technology is to realize the dynamic range compression of electric signal using logafier in detection circuit, should
The dynamic range that technology is capable of effectively expanded laser light radar system rear end Acquisition Circuit still can not solve closely strong echo
Detector saturation problem caused by signal.
Polarization technology is to inhibit dynamic range caused by the echo interference of strong scattering medium using optical polarization method of reseptance
Increase, laser radar cannot be improved in strong scattering medium to the dynamic range of hard goal detection.
Gating technology can be made by optics or electrical method laser radar in certain one-shot measurement only to a certain section away from
From echo-signal carry out corresponding, then repeatedly different distance is detected respectively by adjusting parameter, is realized dynamic to detection
The extension of state range.But the technology needs laser radar to carry out repeatedly detection to meet the time continuity of echo-signal, no
It is suitble to the quick detection application required to detection time.
Synchronous variable-gain technology is by detector gain and laser emission time opening relationships, using Laser emission as starting
Moment quickly improves the gain of detector as time goes by, realizes the change of sensitivity to different distance sounding.The skill
Art has been widely used in ranging and Atmospheric Survey laser radar, but in strong scattering medium, the rising of variable-gain curve
Time often foreshortened within hundred nanoseconds, and so the change in gain of high speed can bring higher noise to detector and circuit,
Influence the stability of signal output.Therefore, for the currently laser radar used in strong scattering medium, the dynamic range of detection
It is still the critical issue for needing to solve and optimize.
Summary of the invention
The purpose of the present invention is to solve the detection dynamics faced when laser radar detects the strong scattering mediums such as water, mist
Range deficiency problem, provides a kind of optical filtering apparatus that transmitance changes with field of view of receiver angle, which utilizes interference filter
The characteristic that piece central wavelength changes with angle of light, it is real on the basis of guaranteeing the big visual field echo light in edge compared with high transmittance
Now to the decaying of center small field of view echo light, spy of the laser radar system in the strong scattering mediums such as water, mist can effectively improve
Survey dynamic range.
The working principle of the invention：
Laser is propagated in strong scattering medium, and the spot diameter of laser can be increased rapidly with propagation distance, shorter
Biggish visual field variation and scattered signal Strength Changes are formed apart from upper, the scattering optical echo signal formed has following special
Point：
1, at closely, optical echo signal concentrates on center small field of view；
2, distant location, optical echo signals disperse to the big visual field in edge；
3, remote optical echo signal strength will be far smaller than the optical echo signal strength of short distance.
Basic principle is the characteristic that the central wavelength of interferometric filter changes with incident light angle：λθ=λ0[1-(Ne/N)2sin2θ]0.5, wherein λ0Central wavelength when being 0 angle incidence of light, Ne are external agency refractive index, and N is optical filter refraction
Rate, θ are angle of incidence of light, λθCentral wavelength when being light θ angle incidence.Pacify on the relaying collimated light path of optics receiving lens
One is filled with temperature controlled bandpass interference filter, the central wavelength of interferometric filter can vary with temperature, by band logical
The temperature of interferometric filter controls, and filter center wavelength when field angle incidence that light edge is big is set as receiving light
Wavelength.When reception light enters from the big field angle in edge, the central wavelength of interferometric filter is consistent with optical wavelength is received, at this time
Optical filtering apparatus transmitance highest.When receive light enter from center small field of view angle when, the central wavelength of interferometric filter with connect
It receives optical wavelength and deviates maximum, optical filtering apparatus transmitance at this time is minimum.The transmitance of the optical filtering apparatus can be with reception
The increase of field angle and increase, therefore, which, can be under the premise of guaranteeing long distance isolated edge big visual field weak signal transmitance
It realizes the inhibition for neglecting field strength echo-signal to short distance center, promotes the dynamic range of echo optical receiving system.
Technical solution of the invention is as follows：
A kind of optical filtering apparatus that transmitance changes with field of view of receiver angle, it is characterized in that：The device includes receiving master
Lens, along the reception main lens optical axis and return laser beam direction be successively field stop, collimation lens, insulation cover front window glass
Glass, interferometric filter, insulation cover rear hatch glass and condenser lens, the field stop is located at the reception main lens
Focal plane, semiconductor cooler and thermistor are mounted on the insulation cover, the front window glass, interferometric filter
It is (parallel with the plane of rear hatch glass；
The reception main lens converges to return laser beam in the field stop, and the field stop only penetrates
Light in field of view of receiver, the light of transmission after the collimation lens collimation by the interferometric filter, through interference
The light of optical filter focuses on subsequent detector by the condenser lens.
Under preset temperature, the central wavelength and reception main lens of the interferometric filter corresponding edge field angle are received
Optical wavelength it is consistent.
The front window glass and rear hatch glass is coated with consistent anti-reflection Jie of wavelength that light is received with reception main lens
Plasma membrane.
The outer surface of the insulation cover is close in one end of the semiconductor cooler, and the other end is mounted on cooling fin
On, the semiconductor cooler is heated or is made to insulation cover according to the measurement temperature of thermistor and the difference of preset temperature
It is cold, by the internal temperature control of insulation cover in preset temperature ± 1 DEG C range.
The advantage of the invention is that：
1, the characteristics of being transmitted in strong scattering medium using laser, the optics that transmitance of the present invention changes with field of view of receiver angle
Filter can effectively inhibit the strong echo-signal near field, and keep the integrality of signal without increasing detection channels；
It 2, can be by the on-line control to interferometric filter temperature, to adjust for the scattering medium of different scattering strengths
The central wavelength of whole interferometric filter changes the saturating of far and near field signal to change transmitance with the change curve of field angle
Rate ratio is crossed, environmental parameter is better adapted to.
Detailed description of the invention
Fig. 1 is the structural block diagram for the optical filtering apparatus that transmitance of the present invention changes with field of view of receiver angle；
In figure：1-receives main lens, 2-field stops, 3-collimation lenses, 4-interferometric filters, 5-insulation covers, 5-
1-insulation cover front screen, 5-2-insulation cover rear window, 6-semiconductor coolers, 6-1-semiconductor cooler for heat dissipation
Piece, 7-thermistors, 8-condenser lenses.
Specific embodiment
Below with reference to example and attached drawing, the invention will be further described, but protection model of the invention should not be limited with this
It encloses.
First referring to Fig. 1, Fig. 1 is the structural frames for the optical filtering apparatus that transmitance of the present invention changes with field of view of receiver angle
Figure, as seen from the figure, transmitance of the present invention include receiving main lens 1, visual field light with the optical filtering apparatus that field of view of receiver angle changes
Late 2, collimation lens 3, interferometric filter 4, insulation cover 5, insulation cover front screen 5-1, insulation cover rear window 5-2, semiconductor
Refrigerator 6, semiconductor cooler for heat dissipation piece 6-1, thermistor 7, condenser lens 8, the connection relationship of above-mentioned component are as follows：
The reception main lens 1 converges to echo of the laser in strong scattering medium in the field stop 2, institute
The field stop stated 2 light penetrated in field of view of receiver, the light of transmission is after the collimation lens 3 collimates by described
Interferometric filter 4 focuses on subsequent detector, the interference by the condenser lens 8 through the light of interferometric filter
Optical filter 4 is mounted in the insulation cover 5, and the semiconductor cooler 6 and thermistor 7 are mounted on the insulation cover
On, it realizes and the temperature of insulation cover is controlled.
Here is the main devices and parameter that one embodiment uses：
The reception main lens 1 be non-spherical lens, clear aperture 200mm, numerical aperture 0.4, wavelength 526.5nm's
Transmitance is 99.9%；
The field stop 2 be one be mounted on receive 1 focal plane of main lens on circular hole diaphragm, aperture 10mm,
With 1 light shaft coaxle of reception main lens；
The collimation lens 3 and condenser lens 8 is non-spherical lens, clear aperture 60mm, numerical aperture 0.4, wavelength
The transmitance of 526.5nm is 99.9%；
20 DEG C of the preset temperature of the interferometric filter 4, the central wavelength for corresponding to the angle 20mrad is 526.5nm, right
The central wavelength for answering the angle 0mrad is 526.9nm.The optical bandwidth of interferometric filter is 0.6nm, incident for 20mrad angle
The transmitance of 526.5nm light be 0.7, and be only 0.002 for the transmitance of the 526.5nm light of 0mrad angle incidence.
The insulation cover 5 includes front screen 5-1 and rear window 5-2, two glass pane planes and interferometric filter 4
Plane it is parallel, before and after being located at interferometric filter, and glass pane is coated with the anti-reflection deielectric-coating of 526.5nm, and transmitance is
99.9%.
The thermistor 7 is mounted on inside insulation cover, for measuring the temperature inside insulation cover.
The outer surface of insulation cover is close in described 6 one end of semiconductor cooler, and the other end is mounted on semiconductor cooler and dissipates
On backing 6-1, insulation cover is heated according to the difference of 7 feedback temperature of thermistor and 20 DEG C of preset temperatures or is freezed, it will
The internal temperature control of insulation cover is in 20 DEG C of ± 1 DEG C of ranges.
Claims (4)
1. the optical filtering apparatus that a kind of transmitance changes with field of view of receiver angle, it is characterized in that：The device includes receiving master thoroughly
Mirror (1) is successively field stop (2), collimation lens (3), insulation cover along reception main lens (1) optical axis and return laser beam direction
(5) front window glass (5-1), interferometric filter (4), insulation cover (5) rear hatch glass (5-2) and condenser lens (8), institute
The field stop (2) stated is located at described reception main lens (1) focal plane, semiconductor cooler (6) and thermistor (7) installation
On the insulation cover (5), the front window glass (5-1), interferometric filter (4) and rear hatch glass (5-2) it is flat
Face is parallel to each other；
The reception main lens (1) converges to return laser beam in the field stop (2), the field stop (2)
Only through the light in field of view of receiver, the light of transmission is after collimation lens (3) collimation by the interferometric filter
(4), subsequent detector is focused on by the condenser lens (8) through the light of interferometric filter.
2. the optical filtering apparatus that transmitance according to claim 1 changes with field of view of receiver angle, it is characterised in that pre-
At a temperature of if, the central wavelength and reception main lens (1) received light wave of the interferometric filter (4) corresponding edge field angle
It is long consistent.
3. the optical filtering apparatus that transmitance according to claim 1 changes with field of view of receiver angle, it is characterised in that described
Front window glass (5-1) and rear hatch glass (5-2) be coated with receive main lens (1) receive light consistent anti-reflection Jie of wavelength
Plasma membrane.
4. the optical filtering apparatus that transmitance according to any one of claims 1 to 3 changes with field of view of receiver angle, feature
Be that the outer surface of the insulation cover is close in one end of the semiconductor cooler (6), the other end be cooling fin (on 6-1,
The semiconductor cooler (6) heats insulation cover according to the measurement temperature of thermistor (7) and the difference of preset temperature
Or refrigeration, the temperature for keeping the insulation cover (5) internal are controlled in preset temperature ± 1 DEG C range.
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| CN105911534B true CN105911534B (en) | 2018-11-20 |
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| CN110441754B (en) * | 2019-07-22 | 2022-08-30 | 中国科学院上海光学精密机械研究所 | Optical receiving device with controllable optical efficiency of subdivided field of view |
| CN110412594A (en) * | 2019-07-22 | 2019-11-05 | 北京光勺科技有限公司 | A kind of laser multi-channel detection system |
| CN115097463A (en) * | 2019-12-20 | 2022-09-23 | 深圳市速腾聚创科技有限公司 | Receiving device, transmitting/receiving device, and laser radar |
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Effective date of registration: 20211210 Address after: No. 19, Hengfei Road, Nanjing Economic and Technological Development Zone, Nanjing, Jiangsu 210046 Patentee after: NANJING INSTITUTE OF ADVANCED LASER TECHNOLOGY Address before: 201800 mail box 800-211, Shanghai, Jiading District, Shanghai Patentee before: SHANGHAI INSTITUTE OF OPTICS AND FINE MECHANICS CHINESE ACADEMY OF SCIENCES |