CN102353998B - Terahertz (THz) video camera for channel security check - Google Patents

Abstract

The invention relates to a road safety inspection THz camera, which is composed of a Stirling refrigeration thermoelectric surface array THz camera and a solid THz remote radiation source of a semiconductor laser optical pump lithium niobate crystal, wherein the Stirling refrigeration thermoelectric surface array THz camera and The solid-state THz remote radiation source of the semiconductor laser optically pumped lithium niobate crystal is aimed at the roadway for reflective THz vision-aided imaging or is aligned with the roadway for THz imaging. The invention has the performance of fully digging and improving THz ray emission energy and THz imaging, realizes a real-time road safety inspection THz camera for the specific application of road safety inspection and the characteristics of THz perspective imaging, can work for a long time in the field, is convenient to use, and has a long life. Realize the purpose of the present invention.

Description

A roadside security inspection THz camera

technical field

The present invention relates to the technical field of radiation imaging and security inspection, in particular to a road security inspection THz camera with a solid THz generator plus Stirling thermoelectric array. The strong THz rays generated by the difference frequency between the lithium niobate crystal rod and its Raman scattered light irradiate the roadway, and the thermoelectric thin film area array cooled by the Stirling machine is used for THz band imaging.

Background technique

Most of the existing terahertz imaging technologies use femtosecond lasers to irradiate nonlinear crystals such as zinc telluride to generate pulsed THz rays for two-dimensional scanning in the time domain, and the nonlinear crystals such as zinc telluride receive scanned THz rays for photoelectric imaging. This method is available for sale by converting and obtaining terahertz imaging signals, but because the point pulses of about tens of times per second cannot scan a large area of human body and objects in a short time, it can only be completed for small objects in a short time Terahertz imaging is less practical.

At present, the laboratory also uses two laser beams with a wavelength difference of about ten nanometers to irradiate a nonlinear crystal for frequency mixing to obtain THz ray output at a difference frequency.

In addition, THz sources such as quantum cascade THz lasers and THz semiconductor lasers that the laboratory is developing are difficult to perform remote reflection THz imaging due to low output power. The free electron THz laser has a large output power, but its volume is very large, so it is not suitable as a vision-aiding radiation source for terahertz photography in road security checks.

If the THz sensor used for photography uses a point sensor for scanning time-domain imaging, the scanning time for one frame of image imaging is too long to be practical; it is suitable to use a fast-imaging THz area sensor for long-term remote road security inspection.

Contents of the invention

The purpose of the present invention is to improve the prior art and provide a roadside security inspection THz camera to achieve the purpose of long-term terahertz reflection imaging or perspective imaging of people and objects on the remote roadway, and to detect the security inspection of dangerous goods carried.

The technical problem that the present invention solves can adopt following technical scheme to realize:

A road safety inspection THz camera is characterized in that it is composed of a Stirling machine cooling thermoelectric surface array THz camera and a solid THz remote radiation source whose optical pump section of a semiconductor laser is a flat arc gate type lithium niobate crystal rod, wherein The solid THz long-distance radiation source with a THz cooling thermoelectric surface array THz camera and a semiconductor laser optical pump whose cross-section is a flat-arc gate type lithium niobate crystal rod is aligned with the roadway for reflective THz vision-aided photography or aligned with the roadway for opposite shooting. THz camera.

In a preferred embodiment of the present invention, the Stirling machine refrigerated thermoelectric surface array THz camera and the semiconductor laser optical pump whose cross-section is a solid THz remote radiation source with a planar arc gate type lithium niobate crystal rod can respectively pass through the first angle. The adjustable bracket and the second angle-adjustable bracket are installed on the pan-tilt, aiming at the person or object on the security check position of the roadway to perform reflective THz vision-aided camera.

The cross-section of the semiconductor laser optical pump is a flat-arc gate type lithium niobate crystal rod. The THz ray emission direction of the solid THz remote radiation source and the imaging direction of the Stirling machine cooling thermoelectric array THz camera are within the road security check intersection at the location.

The adjustment angle of the first angle-adjustable bracket is 0-40 degrees; the adjustment angle of the second angle-adjustable bracket is 0-40 degrees.

In a preferred embodiment of the present invention, the Stirling machine refrigerated thermoelectric surface array THz camera and the solid THz remote radiation source whose cross-section is a planar gate type lithium niobate crystal rod of the semiconductor laser optical pump respectively pass through the first fixed bracket and the second fixed bracket are respectively installed on both sides of the security check position of the walkway, and are aimed at the people or objects on the security check position of the walkway to form opposite shots for THz imaging.

When the Stirling machine refrigerated thermoelectric area THz camera and the solid THz remote radiation source whose cross-section is a flat arc gate type lithium niobate crystal rod are respectively installed on both sides of the roadway security check position, the two The optical axes installed oppositely pass through the center of the security check position, and the average installation height is half a person's height.

In a preferred embodiment of the present invention, the Stirling machine thermoelectric surface array THz camera outputs a video THz camera TV signal through electrical scanning and electrical signal amplification processing, and the electrical scanning frame synchronization phase is locked by the instrument.

In a preferred embodiment of the present invention, the Stirling machine thermoelectric area array THz camera includes:

a camera housing;

A Stirling refrigerator disposed in the middle of the camera housing;

A cold chamber arranged in the housing of the camera and located at the front end of the Stirling refrigerator, the interior of the cold chamber is evacuated and insulated;

A lithium tantalate thin film pyroelectric area sensor disposed in the camera housing and located on the cold wall of the cold store, wherein the pyroelectric induction of the lithium tantalate thin film pyroelectric area sensor is sensitive to the THz band;

The objective lens interface configured in the camera housing and located in front of the optical axis of the lithium tantalate thin film pyroelectric area sensor;

THz objective lens configured on the objective lens interface;

The electronic scanning synchronous control and signal amplification processing circuit board of the THz camera arranged in the camera housing, the signal control pin of the lithium tantalate thin film pyroelectric area sensor leads out of the cold chamber and the THz sensor through a shielded short lead wire. The electric scan synchronous control of the camera is electrically connected to each terminal of the signal amplification processing circuit board;

The power supply module configured in the camera housing, the power supply module supplies power to the electronic scanning synchronous control and signal amplification processing circuit board of the THz camera, the lithium tantalate thin film thermoelectric area sensor and the Stirling refrigerator.

The THz objective lens is a gold reflective objective lens or a refractive THz objective lens with a polyethylene lens.

The Stirling refrigerator is equipped with a 100 atmosphere compressor.

In a preferred embodiment of the present invention, the solid-state THz remote radiation source whose semiconductor laser optically pumped cross-section is a flat-arc gate type lithium niobate crystal rod includes a semiconductor laser optically pumped lithium niobate crystal solid THz generator and is configured in A group of light-condensing beam expanders on the output optical axis of the semiconductor laser optically pumped lithium niobate crystal solid THz generator. The energy is concentrated at a solid angle close to the viewing angle of the Stirling machine thermoelectric surface array THz camera.

The semiconductor laser optically pumped lithium niobate crystal solid THz generator uses a semiconductor laser as a pumping source to generate 1064nm coherent pulsed laser light by pumping a Nd:YAG resonant element and adding a tuner.

The frequency of the 1064nm coherent short-pulse laser is an integer multiple of the imaging frame rate of the Stirling machine thermoelectric array THz camera, and the phase is locked in the non-blanking period.

The semiconductor laser optically pumped lithium niobate crystal solid THz generator includes

A generator housing; the set of condenser beam expanders is arranged at the front end of the generator housing;

a semiconductor laser arranged at the rearmost end of the generator housing;

Nd:YAG resonant element and electro-optic tuner arranged in the generator housing and on the output optical axis of the semiconductor laser at the front end of the semiconductor laser;

The cross-section arranged in the generator housing and positioned on the output optical axis of the front end of the Nd:YAG resonant element is a flat arc gate type lithium niobate crystal rod, and the 1064nm coherent pulse laser generated by the pumping Nd:YAG resonant element has a great impact on the The lithium niobate crystal rod is optically pumped, so that the lithium niobate crystal generates pump light and Raman light to mix and emit THz, which is output by the group of light-condensing beam expanders;

A power supply and a control part are arranged in the housing of the generator, and the power supply and control part supply power to the semiconductor laser and control the operation of the semiconductor laser.

In a preferred embodiment of the present invention, a first collimating mirror is arranged in the housing of the generator, and the first collimating mirror is located on the semiconductor laser between the semiconductor laser and the Nd:YAG resonant element. On the output optical axis of the laser, the first collimating mirror converges the laser light emitted by the semiconductor laser into a thinner strong laser beam and injects it into the Nd:YAG resonant element, and the electro-optic light is applied on the optical axis of the resonant cavity. The tuner generates 1064nm coherent pulsed laser light.

In a preferred embodiment of the present invention, a second collimating mirror is disposed in the generator housing, and the second collimating mirror is located between the Nd:YAG resonant element and the lithium niobate crystal rod On the optical axis between them, the second collimating mirror converges the 1064nm coherent pulsed laser pumped by the Nd:YAG resonant element into a thinner intense laser beam aimed at the lithium niobate crystal, so that the niobate The lithium crystal generates 1064nm pump light and Raman scattered idler light, and the difference frequency radiation in its own nonlinear mixing is output in the THz band ray, which is output by the set of condensing beam expanders.

In a preferred embodiment of the present invention, the shape of the lithium niobate crystal rod is a planar gate structure in cross-section, so as to enhance the radiation waveguide effect on the pump source.

In a preferred embodiment of the present invention, a THz wavelength grating is engraved on the flat side of the lithium niobate crystal to further increase the energy of THz rays output along the THz wavelength grating and reduce crystal absorption.

In a preferred embodiment of the present invention, a reflector is provided at the normal to the output direction of the THz wavelength grating and at both ends of the lithium niobate crystal to reduce the end face loss of the lithium niobate crystal and increase the emission energy and efficiency of THz rays.

In a preferred embodiment of the present invention, a 1064nm reflector is disposed inside the generator casing, and the 1064nm reflector is located on the optical axis in front of the lithium niobate crystal.

In a preferred embodiment of the present invention, the Nd:YAG resonant element is composed of a Nd:YAG crystal rod, an electro-optic Q-switched mode locker, and a front and rear resonant concave mirror, wherein the rear resonant concave mirror is located on the Nd: On the output optical axis of the semiconductor laser at the input end of the YAG crystal rod, the electro-optic Q-switching mode locker is located on the output optical axis of the semiconductor laser at the output end of the Nd:YAG crystal rod, and the front resonant concave mirror is located at the electro-optic Q-switching lock The semiconductor laser at the output end of the modulator is on the output optical axis, where the Nd:YAG crystal rod generates 1064nm coherent pulsed laser light under the pumping of the semiconductor laser, and is phase-locked by the electro-optical Q-switched mode-locker in the non-blanking period.

In a preferred embodiment of the present invention, the optical distance between the front and rear resonant concave mirrors is 1/2 plus n wavelengths.

In a preferred embodiment of the present invention, the front resonant concave mirror is a transflective 1064 nm resonant concave mirror, and the rear resonant concave mirror is a fully transparent 808 nm fully reflective 1064 nm resonant concave mirror.

In a preferred embodiment of the present invention, the semiconductor laser is an 808nm semiconductor laser.

The roadway security inspection THz camera of the present invention is composed of a Stirling machine cooling thermoelectric surface array THz camera and a semiconductor laser optical pump with a solid THz remote radiation source whose cross-section is a flat-arc gate type lithium niobate crystal rod, and has the ability to fully excavate and improve THz radiation. The output energy and THz imaging performance can work for a long time in the field, easy to use, and long life.

The features of the present invention can be clearly understood by referring to the drawings of the present invention and the detailed description of the following preferred embodiments.

Description of drawings

FIG. 1 is a schematic diagram of the application layout of Embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of the application layout of Embodiment 2 of the present invention.

Fig. 3 is a structural schematic diagram of the THz camera head of the Tring cooling thermoelectric array of the present invention.

Fig. 4 is a schematic structural diagram of a solid THz remote radiation source of a semiconductor laser optically pumped lithium niobate crystal of the present invention.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the patent will be further elaborated below in conjunction with specific illustrations.

Example 1

As shown in Figure 1, the roadside security inspection THz camera of the present invention is composed of a Stirling refrigeration thermoelectric surface array THz camera 100 and a solid THz remote radiation source 200 of a semiconductor laser optically pumped lithium niobate crystal, and the Stirling refrigeration thermoelectric surface array The THz camera 100 and the solid THz remote radiation source 200 of the semiconductor laser light-pumped lithium niobate crystal are respectively installed on a pan-tilt 600 through the angle-adjustable brackets 400 and 500, and the solid THz remote radiation source 200 of the semiconductor laser light-pumped lithium niobate crystal is installed on a platform 600. The THz ray emission direction 200a of the Stirling refrigeration thermoelectric area THz camera 100 intersects with the imaging direction 100a of the Stirling refrigeration thermoelectric area THz camera 100 at the security check position of the roadway, and the reflective THz vision-aided camera is performed on the people and objects 300 being security-checked on the roadway. Angles of the solid THz remote radiation source 200 of the Stirling cooling thermoelectric surface array THz camera 100 and the semiconductor laser optically pumped lithium niobate crystal can be adjusted respectively through the angle adjustable brackets 400 and 500 .

Example 2

Referring to Fig. 2, the roadway security inspection THz camera of the present invention is composed of a Stirling refrigeration thermoelectric surface array THz camera 100 and a solid THz remote radiation source 200 of a semiconductor laser optically pumped lithium niobate crystal, wherein the Stirling refrigeration thermoelectric surface array THz The camera 100 and the solid THz remote radiation source 200 of the semiconductor laser optical pump lithium niobate crystal are respectively installed at half a person's height on both sides of the roadside security check position through the fixed brackets 710 and 720, and the Stirling refrigeration thermoelectric area array THz camera 100 The optical axis of the solid THz remote radiation source 200 and the semiconductor laser optically pumped lithium niobate crystal are parallel to the height of half a person.

The THz ray emission direction 200a of the solid THz remote radiation source 200 of the semiconductor laser optical pump lithium niobate crystal is opposite to the imaging direction 100a of the Stirling refrigeration thermoelectric array THz camera 100. radiate for THz imaging.

Referring to Fig. 3, the Stirling thermoelectric surface array THz camera 100 in the above embodiment includes a camera housing 160, a Stirling refrigerator 110 is arranged in the middle of the camera housing 160, and the Stirling refrigerator 110 is configured There is a compressor of 100 atmospheres. A cold chamber 112 is provided at the front end of the Stirling refrigerator. The cold storehouse 112 uses a mirror-polished polyethylene thin plate 122 as a window, and the cold storeroom is evacuated and insulated. A lithium tantalate film pyroelectric area sensor 120 with a thickness of less than 4 microns is placed on the cold wall of the cold chamber 112 and cooled to about 90K. The signal control pin of the lithium tantalate film pyroelectric area sensor 120 is led out of the cold chamber 112 through a shielded short lead wire and is electrically connected with each terminal point of the electronic scanning synchronous control and signal amplification processing circuit board 130 of the THz camera, and the electronic scanning synchronous control and The signal amplification processing circuit board 130 and the Stirling refrigerator 110 are powered by the power module 140 .

In front of the optical axis of the lithium tantalate thin film pyroelectric area sensor 120, the objective lens interface 124 is set according to the back focus of the objective lens, and a THz objective lens 150 with a suitable focal length suitable for the security inspection distance and field of view is equipped. The THz objective lens is a reflective objective lens or a refractive THz objective lens with a polyethylene lens.

The Stirling pyroelectric area array THz camera 100 outputs a THz camera TV signal through electrical scanning and electrical signal amplification processing, and the electrical scanning frame synchronization phase is locked by the instrument for THz imaging.

Referring to Fig. 4, the solid THz remote radiation source 200 of the semiconductor laser optically pumped lithium niobate crystal solid THz generator in the above-mentioned embodiment comprises a semiconductor laser optically pumped lithium niobate crystal solid THz generator and is configured in the semiconductor laser optically pumped lithium niobate crystal solid state A set of condenser beam expanders 250 in the THz output direction of the THz generator. And the semiconductor laser optical pump lithium niobate crystal solid THz generator comprises a generator housing 270, an 808nm semiconductor laser 210 is arranged at the rear end in the generator housing 270, and in the generator housing 270, an 808nm semiconductor laser 210 The front end is sequentially provided with a collimating mirror 212, a Nd:YAG resonant element 220, a collimating mirror 232, a lithium niobate crystal 234 with a planar arc gate cross section, a 1064nm reflector 236, and an 808nm semiconductor laser 210. It is on the same optical axis with the collimating mirror 212, the Nd:YAG resonant element 220, the collimating mirror 232, the lithium niobate crystal 234 with a flat arc gate shape in cross-section, and the 1064nm reflector 236.

The Nd:YAG resonant element 220 includes a Nd:YAG crystal rod 222, an electro-optic Q-switched mode locker 224, and front and rear resonant concave mirrors 226 and 228, wherein the rear resonant concave mirror 226 is located behind the input end of the Nd:YAG crystal rod 222 side, the electro-optic Q-switching mode locker 224 is located at the front side of the Nd:YAG crystal rod 222 output end, and the front resonant concave mirror 228 is located at the front side of the electro-optic Q-switching mode locker 224 output end, the Nd:YAG crystal rod 222, the electro-optic Q-switching locker The molder 224 and the front and rear resonant concave mirrors 226, 228 are located on the same optical axis. The front resonant concave mirror 228 is a semi-transparent and semi-reflective 1064nm resonant concave mirror, and the rear resonant concave mirror 226 is a fully transparent 808nm and fully reflective 1064nm resonant concave mirror. The optical path between them is 1/2 plus n wavelengths.

The laser beam emitted by the 808nm semiconductor laser 210 is converged by the collimating mirror 212 to produce a thinner strong laser beam to pump the Nd:YAG crystal rod 222 to generate a 1064nm coherent pulsed laser which is phase-locked by the electro-optical Q-switched mode-locker 224 in the non-destructive Hidden period. The pulse frequency of the 1064nm coherent pulsed laser is set at an integer multiple of the imaging frame rate of the Stirling cooling thermoelectric array THz camera 100 .

The Nd:YAG crystal rod 222 outputs a 1064nm pulsed laser beam to align with the lithium niobate crystal 234 for optical pumping, so that the pumping light generated by the lithium niobate crystal 234 is mixed with Raman scattered light to emit THz rays. Select the size and shape of the lithium niobate crystal 234 to make the radiation waveguide strong, engrave the THz wave exit grating 238 on the side of the lithium niobate crystal to reduce the absorption of the THz wave; and in the normal direction of the THz output direction, the lithium niobate crystal 234 Silicon reflectors 240 and 240a are provided at both ends to increase the coupling and radiation intensity to maximize the output THz wave power.

A group of condenser beam expanders 250 are arranged at the front end of the generator housing 270. The group of condenser beam expanders 250 are located in the THz output direction, and concentrate the output energy of the lithium niobate crystal 234 in the field of view of the THz camera objective lens. Solid angles with similar angles emerge. When the irradiation position of the solid THz remote radiation source 200 of the semiconductor laser light-pumped lithium niobate crystal is adjusted in the shooting field of view of the Stirling refrigeration thermoelectric array THz camera 100, the irradiation of people and objects on the roadside security inspection through THz waves is used to aid vision , The roadside security inspection THz camera outputs the video signal of the strong and weak image of the THz wave reflection or penetration of the security inspection person and object.

The power supply and control unit 260 arranged in the generator casing 270 supplies power to the semiconductor laser 210 and controls the operation of the semiconductor laser 210 .

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Various changes and improvements fall within the scope of the claimed invention, which is defined by the appended claims and their equivalents.

Claims (21)

1. a trade safety check THz video camera, it is characterized in that, the long-range radiation source of solid body THz that is flat arc gate-type lithium columbate crystal rod by Stirling-electric hybrid refrigeration thermoelectricity face battle array THz camera and semiconductor laser optical pumping cross section forms, and the long-range radiation source of solid body THz that wherein Stirling-electric hybrid refrigeration thermoelectricity face battle array THz camera is flat arc gate-type lithium columbate crystal rod with semiconductor laser optical pumping cross section is aimed at trade and carried out reflective THz and help and look shooting or aim at the relative correlation in trade and carry out the THz shooting.

2. trade safety check THz video camera as claimed in claim 1, it is characterized in that, the long-range radiation source of solid body THz that described Stirling-electric hybrid refrigeration thermoelectricity face battle array THz camera and semiconductor laser optical pumping cross section are flat arc gate-type lithium columbate crystal rod is installed on a The Cloud Terrace by the first angle adjustable support and the second angle adjustable support respectively, aims at the locational people of described trade safety check or thing and carries out reflective THz and help and look shooting.

3. trade safety check THz video camera as claimed in claim 2, it is characterized in that, the shooting direction of the THz ray exit direction of the long-range radiation source of solid body THz that described semiconductor laser optical pumping cross section is flat arc gate-type lithium columbate crystal rod and described Stirling-electric hybrid refrigeration thermoelectricity face battle array THz camera crosses in safety check position, described trade.

4. trade safety check THz video camera as claimed in claim 2, is characterized in that, the adjusting angle of described the first angle adjustable support is 0～40 degree; The adjusting angle of described the second angle adjustable support is 0～40 degree.

5. trade safety check THz video camera as claimed in claim 1, it is characterized in that, the long-range radiation source of solid body THz of described stirling refrigeration thermoelectricity face battle array THz camera and semiconductor laser optical pumping lithium columbate crystal respectively by the first fixed support and the second fixed support respectively in opposite directions optical axis as one man be arranged on the both sides of safety check position, described trade, optical axis forms correlation through the locational people of described trade safety check or thing half people's At The Height and carries out the THz shooting in opposite directions.

6. trade safety check THz video camera as claimed in claim 1, it is characterized in that, described stirling refrigeration thermoelectricity face battle array THz camera amplifies processing output video THz shooting TV signal by electric scanning and electric signal and electric scanning frame synchronization phase place is locked by instrument.

7. as the described trade safety check of claim 1 to 6 any one claim THz video camera, it is characterized in that, described stirling refrigeration thermoelectricity face battle array THz camera comprises:

One camera housing;

Be configured in the sterlin refrigerator in centre position in described camera housing;

Be configured in described camera housing and be positioned at the cold storehouse of the front end of described sterlin refrigerator, vacuumizing heat insulation in described cold storehouse;

Be configured in described camera housing and be positioned at the lithium tantalate thin film thermoelectricity area array sensor on the cold wall in cold storehouse, wherein said lithium tantalate thin film thermoelectricity area array sensor thermoelectricity induction reaches THz wave band sensitivity;

Be configured in described camera housing and be positioned at the front object lens interface of lithium tantalate thin film thermoelectricity area array sensor optical axis;

Be configured in the THz object lens on the object lens interface;

Be configured in electric scanning synchro control and the signal processing circuit plate of the THz camera in described camera housing, the signal controlling pin of described lithium tantalate thin film thermoelectricity area array sensor is drawn outside cold storehouse and is electrically connected to each end points of signal processing circuit plate with the electric scanning synchro control of described THz camera by the short leg of shielding;

Be configured in the power module in described camera housing, described power module is given electric scanning synchro control and signal processing circuit plate, lithium tantalate thin film thermoelectricity area array sensor and the sterlin refrigerator power supply of described THz camera.

8. trade safety check THz video camera as claimed in claim 7, is characterized in that, described THz object lens are golden face catoptric lens or with the refraction type THz object lens of tygon eyeglass.

9. trade safety check THz video camera as claimed in claim 7, is characterized in that, described sterlin refrigerator disposes 100 atmospheric compressors.

10. as the described trade safety check of claim 1 to 6 any one claim THz video camera, it is characterized in that, the long-range radiation source of solid body THz that described semiconductor laser optical pumping cross section is flat arc gate-type lithium columbate crystal rod comprises semiconductor laser instrument optical pumping lithium columbate crystal solid body THz generator and is configured in one group of optically focused beam expanding lens on described semiconductor laser optical pumping lithium columbate crystal solid body THz generator THz outbound course, the concentration of energy that described one group of optically focused beam expanding lens is exported semiconductor laser optical pumping lithium columbate crystal solid body THz generator is in the solid angle outgoing close with described stirling refrigeration thermoelectricity face battle array THz camera field angle.

11. trade safety check THz video camera as claimed in claim 10, it is characterized in that, described semiconductor laser optical pumping lithium columbate crystal solid body THz generator is made pumping source through pumping Nd:YAG resonant element and electro-optical tuning and is produced 1064nm coherent pulse laser by semiconductor laser.

12. trade safety check THz video camera as claimed in claim 11, is characterized in that, the frequency of the relevant short-pulse laser of described 1064nm is the integral multiple of shooting frame frequency of described stirling refrigeration thermoelectricity face battle array THz camera and phase-locked at non-black-out intervals.

13. trade safety check THz video camera as claimed in claim 11, is characterized in that, described semiconductor laser optical pumping lithium columbate crystal solid body THz generator, comprise

One generator body; Described one group of optically focused beam expanding lens is configured in described generator body foremost;

Be configured in the semiconductor laser of rearmost end in described generator body;

Be configured in described generator body and be positioned at the Nd:YAG resonant element on the semiconductor laser output optical axis of semiconductor laser front end;

Be configured in described generator body and be positioned at the lithium columbate crystal on the semiconductor laser output optical axis, the 1064nm coherent pulse laser that described Nd:YAG resonant element produces carries out optical pumping to described lithium columbate crystal, make lithium columbate crystal produce pump light and Raman light mixing emission THz, by described one group of optically focused beam expanding lens output;

Be configured in power supply and control assembly in described generator body, described power supply and control assembly power and control semiconductor laser work to described semiconductor laser.

14. trade safety check THz video camera as claimed in claim 13, it is characterized in that, dispose one first poly-collimating mirror in described generator body, the described first poly-collimating mirror is on the semiconductor laser output optical axis between described semiconductor laser and described Nd:YAG resonant element, the laser convergence that this first poly-collimating mirror penetrates described semiconductor laser becomes a branch of thinner intense laser beam to inject in described Nd:YAG resonant element, through the pumping of Nd:YAG resonant element, produces 1064nm coherent pulse laser.

15. trade safety check THz video camera as claimed in claim 13, it is characterized in that, dispose one second poly-collimating mirror in described generator body, the described second poly-collimating mirror is on the semiconductor laser output optical axis between described Nd:YAG resonant element and described lithium columbate crystal, the 1064nm coherent pulse laser convergence that this second poly-collimating mirror goes out the pumping of described Nd:YAG resonant element becomes a branch of thinner intense laser beam to aim at described lithium columbate crystal, the ideler frequency light that makes lithium columbate crystal produce 1064nm pump light and Raman scattering in self non-linear frequency mixing the difference frequency radiant output at THz wave band ray, by described one group of optically focused beam expanding lens output.

16. trade safety check THz video camera as claimed in claim 11, is characterized in that, in the flat side of described lithium columbate crystal, engraves the THz wave length grating.

17. trade safety check THz video camera as claimed in claim 11, is characterized in that, at normal, lithium columbate crystal rod two ends of THz wave length grating outbound course, respectively establishes a catoptron.

18. trade safety check THz video camera as claimed in claim 13, it is characterized in that, described Nd:YAG resonant element is by the Nd:YAG crystal bar, electric-optically Q-switched mode locker and front, rear resonance concave mirror forms, wherein said rear resonance concave mirror is positioned on the semiconductor laser output optical axis of described Nd:YAG crystal bar input end, described electric-optically Q-switched mode locker is positioned on the semiconductor laser output optical axis of described Nd:YAG crystal bar output terminal, described front resonance concave mirror is positioned on the semiconductor laser output optical axis of described electric-optically Q-switched mode locker output terminal, wherein the Nd:YAG crystal bar produces 1064nm coherent pulse laser under diode-end-pumped, and phase-locked at non-black-out intervals by electric-optically Q-switched mode locker.

19. trade safety check THz video camera as claimed in claim 18, is characterized in that, the light path between described forward and backward resonance concave mirror is 1/2 to add n wavelength.

20. trade safety check THz video camera as claimed in claim 18, is characterized in that, the resonance concave mirror that described front resonance concave mirror is semi-transparent semi-reflecting 1064nm, and described rear resonance concave mirror is the be all-trans resonance concave mirror of 1064nm of full impregnated 808nm.

21. trade safety check THz video camera as claimed in claim 11 is characterized in that described semiconductor laser is the 808nm semiconductor laser.

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