An integrated medium-wave infrared laser radar transmitting device

Abstract

The present invention discloses an integrated medium-wave infrared laser radar transmitting device, comprising an LD pumped laser light source, a laser crystal, a nonlinear frequency doubling crystal and a filter arranged in sequence; the LD pumped laser light source is used as a light source to emit laser to the laser crystal; the laser crystal is used to generate pulsed laser to the nonlinear frequency doubling crystal; the nonlinear frequency doubling crystal is used to double the laser frequency; the filter is used to filter out part of the laser light beam after the frequency doubling; the LD pumped laser light source, the laser crystal, the nonlinear frequency doubling crystal and the filter are an integrated packaging structure, and generate medium-wave infrared laser output. The laser radar of the present invention generates medium-wave infrared laser output, and emits the laser in a scanning form, realizing multi-angle scanning of radar transmitting end signals.

Description

Technical Field

[0001] The invention belongs to the field of laser technology, and in particular relates to an integrated medium-wave infrared laser radar transmitting device. Background Art

[0002] LiDAR is a radar system based on the TOF principle that emits laser beams to detect the position, speed and other characteristic quantities of a target. It is widely used in military and civilian fields. LiDAR has great potential in the field of intelligent driving, but it is difficult to be widely used due to many unsolvable technical problems, such as: the laser band is difficult to separate from the spectrum accepted by the currently widely used monitoring system, so it will interfere with the existing monitoring system; the laser may cause harm to the human eye when used; it is easily interfered by sunlight. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an integrated medium-wave infrared laser radar transmitting device to solve the problems that the existing laser radar is prone to interfere with the monitoring system, is harmful to the human eye and is easily interfered by sunlight.

[0004] The present invention provides the following technical solutions:

[0005] An integrated medium-wave infrared laser radar transmitting device comprises an LD pump laser light source, a laser crystal, a nonlinear frequency doubling crystal and a filter arranged in sequence;

[0006] The LD pump laser light source is used as a light source to emit laser light to the laser crystal;

[0007] The laser crystal is used to generate pulsed laser to emit to the nonlinear frequency doubling crystal;

[0008] The nonlinear frequency doubling crystal is used to double the frequency of the laser;

[0009] The filter is used to filter out part of the laser beam after frequency doubling;

[0010] The LD pump laser light source, laser crystal, nonlinear frequency doubling crystal and filter are an integrated packaging structure and generate medium-wave infrared laser output.

[0011] Preferably, the LD pump laser light source emits laser light with a wavelength of 808 nm.

[0012] Preferably, the laser crystal is a Nd:YAG crystal, which generates a 1064nm laser. Along the laser transmission direction, a Q-switched crystal is bonded or grown on the laser crystal, and the Q-switched crystal is a Cr:YAG crystal, which generates a Q-switched pulse.

[0013] Preferably, along the laser transmission direction, the incident surface and the exit surface of the laser crystal are respectively coated with a first light control film group and a second light control film group, and the first light control film group and the second light control film group both include a plurality of high-transmittance films and high-reflection films arranged in any order.

[0014] Preferably, the nonlinear frequency doubling crystal is one of a PPLN crystal, a PPKTP crystal and a PPGaAs crystal.

[0015] Preferably, along the laser transmission direction, the incident surface of the nonlinear frequency doubling crystal is cut according to the Brewster angle, and the exit surface is coated with a third light control film group, and the third light control film group includes a high reflection film, a first partial reflection film and a second partial reflection film arranged in any order.

[0016] Preferably, the wavelength band reflected by the high-reflective film is 1064 nm, and the wavelength band reflected by the first partial reflective film and the second partial reflective film is 1.6 μm or 3 μm.

[0017] Preferably, the filter filters out other light beams outside the 3 μm band required for output.

[0018] Preferably, the first micro-vibration mirror and the second micro-vibration mirror are also included, and the rotation axes are perpendicular to each other. The first micro-vibration mirror is driven to rotate by the first piezoelectric ceramic, and the second micro-vibration mirror is driven to rotate by the second piezoelectric ceramic.

[0019] Preferably, the materials used for the first micro-vibration mirror and the second micro-vibration mirror are germanium sheets or sapphire. Compared with the prior art, the beneficial effects of the present invention are:

[0020] (1) The present invention includes an LD pumped laser light source, a laser crystal, a nonlinear frequency doubling crystal and a filter arranged in sequence. The LD pumped laser light source is used as a light source to emit laser light to the laser crystal. The laser crystal is used to generate pulsed laser light to emit to the nonlinear frequency doubling crystal. The nonlinear frequency doubling crystal is used to double the laser light frequency. The filter is used to filter out part of the laser light beam after doubled frequency. The laser radar generates medium-wave infrared laser output and emits the laser light in a scanning form, thereby realizing multi-angle scanning of radar transmitting end signals. The medium-wave infrared laser band is separate from the spectrum band accepted by the monitoring system widely used at this stage, so it will not interfere with the existing monitoring system. The laser in the medium-wave infrared band has strong absorption in water. Since the main component of the human eyeball structure is water, the medium-wave infrared laser can be absorbed by the water in the eye tissue without causing damage to its tissue structure. Therefore, it is safe for the human eye in daily use. The medium-wave infrared laser has a band of 3μm and is therefore not affected by sunlight.

[0021] (2) In the present invention, the LD pump laser light source, laser crystal, nonlinear frequency doubling crystal and filter are an integrated packaging structure with a small size, simple structure and uniform heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a structural diagram of the laser radar in the present invention;

[0023] Marked in the figure are: 1. LD pumped laser light source; 2. first light control film group; 3. laser crystal; 4. Q-switched crystal; 5. second light control film group; 6. nonlinear frequency doubling crystal; 7. third light control film group; 8. filter; 9. first piezoelectric ceramic; 10. first micro-galvanometer; 11. second micro-galvanometer; 12. second piezoelectric ceramic. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0025] like Figure 1 As shown, an integrated medium-wave infrared laser radar transmitting device includes an LD pumped laser light source 1, a laser crystal 3, a nonlinear frequency doubling crystal 6 and a filter 8 which are arranged in sequence; the LD pumped laser light source 1 is used as a light source to emit laser to the laser crystal 3; the laser crystal 3 is used to generate pulsed laser to emit to the nonlinear frequency doubling crystal 6; the nonlinear frequency doubling crystal 6 is used to double the frequency of the laser; the filter 8 is used to filter out part of the light beam of the doubled laser; the LD pumped laser light source 1, the laser crystal 3, the nonlinear frequency doubling crystal 6 and the filter 8 are an integrated packaging structure, and generate medium-wave infrared laser output.

[0026] The LD pump laser light source 1 emits laser light with a wavelength of 808 nm.

[0027] The laser crystal 3 is a Nd:YAG crystal, which generates a 1064nm laser. Along the laser transmission direction, a Q-switched crystal 4 is bonded or grown on the laser crystal 3, and the Q-switched crystal 4 is a Cr:YAG crystal, which generates a Q-switched pulse.

[0028] Along the laser transmission direction, the incident surface and the exit surface of the laser crystal 3 are respectively coated with the first light control film group 2 and the second light control film group 5; the first light control film group 2 is sequentially coated with an 808nm high-transmittance film and a 1064nm high-reflection film, or sequentially coated with a 1064nm high-reflection film and an 808nm high-transmittance film; the second light control film group 5 is sequentially coated with a 1064nm high-transmittance film, a 3μm high-reflection film and a 1.6μm high-reflection film, or sequentially coated with a 3μm high-reflection film, a 1.6μm high-reflection film and a 1064nm high-transmittance film. The order of the high-reflection film and the high-transmittance film in the first light-control film group 2 and the second light-control film group 5 does not affect the result. Their function is to control the amount of light entering and exiting. The function of the 808nm high-transmittance film is to increase the entry of 808nm light, the function of the 1064nm high-reflection film is to reduce the entry of 1064nm light, the function of the 1064nm high-transmittance film is to increase the entry of 1064nm light, the function of the 3μm high-reflection film is to reduce the entry of 3μm light, and the function of the 1.6μm high-reflection film is to reduce the entry of 1.6μm light. The incident surface and the exit surface of the laser crystal 3 are parallel to each other and perpendicular to the direction of the laser beam.

[0029] The nonlinear frequency doubling crystal 6 is one of a PPLN crystal, a PPKTP crystal and a PPGaAs crystal. Along the laser transmission direction, the incident surface of the nonlinear frequency doubling crystal 6 is cut according to the Brewster angle, and its function is to generate polarized light; the exit surface is coated with a third light control film group 7, and the third light control film group 7 includes a 1064nm high reflection film, a 3μm partial reflection film and a 1.6μm partial reflection film, or a 3μm partial reflection film, a 1.6μm partial reflection film and a 1064nm high reflection film. The order of the high reflection film and the partial reflection film does not affect the result. The function of the coating is to control the amount of light entering and exiting. The function of the 1064nm high reflection film is to reduce the entry of 1064nm light, the function of the 3μm partial reflection film is to control the partial entry of 3μm light, and the function of the 1.6μm partial reflection film is to control the partial entry of 1.6μm light. The exit surface of the nonlinear frequency doubling crystal is perpendicular to the direction of the laser beam.

[0030] The function of the filter 8 is to filter out 1.6 μm light and allow 3 μm light to enter. The incident surface and the exit surface of the filter 8 are parallel to each other and perpendicular to the direction of the laser beam.

[0031] The integrated medium-wave infrared laser radar transmitting device provided in this embodiment also includes a first micro-vibration mirror 10 and a second micro-vibration mirror 11 whose rotation axes are perpendicular to each other. The first micro-vibration mirror 10 is driven to rotate by the first piezoelectric ceramic 9, and the second micro-vibration mirror 11 is driven to rotate by the second piezoelectric ceramic 12. The first piezoelectric ceramic 9 and the second piezoelectric ceramic 12 are controlled by electrical signals, and the materials used for the first micro-vibration mirror 10 and the second micro-vibration mirror 11 are germanium sheets or sapphire.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An integrated medium-wave infrared laser radar transmitting device, characterized in that: It includes an LD pump laser light source, a laser crystal, a nonlinear frequency doubling crystal and a filter which are arranged in sequence; The LD pump laser light source is used as a light source to emit laser light to the laser crystal; The laser crystal is used to generate pulsed laser to emit to the nonlinear frequency doubling crystal; The nonlinear frequency doubling crystal is used to double the frequency of the laser; The filter is used to filter out part of the laser beam after frequency doubling; The LD pump laser light source, laser crystal, nonlinear frequency doubling crystal and filter are an integrated packaging structure, and generate medium-wave infrared laser output; Along the laser transmission direction, the incident surface and the exit surface of the laser crystal are respectively coated with a first light control film group and a second light control film group, the first light control film group is sequentially coated with an 808nm high-transmittance film and a 1064nm high-reflection film, or sequentially coated with a 1064nm high-reflection film and an 808nm high-transmittance film; the second light control film group is sequentially coated with a 1064nm high-transmittance film, a 3μm high-reflection film and a 1.6μm high-reflection film, or sequentially coated with a 3μm high-reflection film, a 1.6μm high-reflection film and a 1064nm high-transmittance film; Along the laser transmission direction, the incident surface of the nonlinear frequency doubling crystal is cut according to the Brewster angle, and the exit surface is coated with a third light control film group, which includes a 1064nm high reflection film, a 3μm partial reflection film and a 1.6μm partial reflection film coated in sequence, or a 3μm partial reflection film, a 1.6μm partial reflection film and a 1064nm high reflection film coated in sequence.

2. The integrated medium-wave infrared laser radar transmitting device according to claim 1 is characterized in that: The LD pump laser light source emits laser light with a wavelength of 808 nm.

3. The integrated medium-wave infrared laser radar transmitting device according to claim 1 is characterized in that: The laser crystal is a Nd:YAG crystal, which generates a 1064nm laser. Along the laser transmission direction, a Q-switched crystal is bonded or grown on the laser crystal, and the Q-switched crystal is a Cr:YAG crystal, which generates a Q-switched pulse.

4. The integrated medium-wave infrared laser radar transmitting device according to claim 1 is characterized in that: The nonlinear frequency doubling crystal is one of a PPLN crystal, a PPKTP crystal and a PPGaAs crystal.

5. The integrated medium-wave infrared laser radar transmitting device according to claim 1 is characterized in that: The filter removes other light beams outside the 3 μm band required for output.

6. The integrated medium-wave infrared laser radar transmitting device according to claim 1, characterized in that: The first micro-vibration mirror is driven to rotate by a first piezoelectric ceramic, and the second micro-vibration mirror is driven to rotate by a second piezoelectric ceramic.

7. The integrated medium-wave infrared laser radar transmitting device according to claim 6 is characterized in that: The materials used for the first micro-vibration mirror and the second micro-vibration mirror are germanium sheets or sapphire.

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