Quick-start random jitter delay emission laser device and output method

Abstract

The invention relates to the technical field of laser, and provides a quick-start random jitter delay emission laser device and an output method, and relates to the technical field of laser, the quick-start random jitter delay emission laser device comprises a piezoelectric ceramic total reflective mirror, a laser crystal, a total reflective mirror, an LD array side pumping source, a rectangular prism, an acousto-optic modulator, a driving signal generator, a random jitter delay controller and an output mirror; the piezoelectric ceramic total reflective mirror, the total reflective mirror and the rectangular prism form a long pulse waiting L-shaped resonant cavity. According to the quick-start random jitter delayed emission laser device provided by the invention, on one hand, the acousto-optic modulator is arranged to realize cavity emptying, and the laser emission time is shortened to realize quick start; and on the other hand, the laser emission time is changed by changing the time sequence random number so as to realize delay jitter, and the anti-interference performance of the multi-path laser radar is realized by presetting n groups of time sequence random numbers in advance, changing the preset time sequence random numbers and outputting different pulse lasers.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, in particular to a fast-start random jitter delayed emission laser device and an output method. Background Art

[0002] LiDAR uses laser beams to measure the distance to a target. It has the characteristics of high precision and high spatial resolution and has been widely used in many fields such as topographic surveying, self-driving cars, archeology, urban planning, atmospheric research, power and infrastructure monitoring, etc. Considering the safety of laser wavelength to human eyes and the absorption and scattering of laser by the atmosphere, 1064nm band solid lasers are often used.

[0003] In order to improve the stability of LiDAR in complex environments, especially when multiple LiDARs are used in the same scene, which may cause crosstalk, the existing technology uses random delay jitter to inject into the time interval of the LiDAR startup emission time sequence, thereby changing the laser emission time. However, lasers have an inherent startup time, and as the years of use increase, the startup time becomes longer and longer, and it is unpredictable, resulting in the inability to accurately determine the reception time of the expected echo.

[0004] Therefore, realizing a fast-start random delay jitter emission laser is an important research direction in the development of lidar. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a fast-start random jitter delayed laser emission device and output method, which solves the problems raised in the above-mentioned background technology.

[0007] (II) Technical solution

[0008] Refer to the following Figure 1 to Figure 2 A fast-start random-jitter delayed-emission laser device provided by an embodiment of the present invention is described.

[0009] The present invention proposes a fast-start random jitter delay laser emission device, such as Figure 1 shown.

[0010] According to one aspect of the present invention, Figure 1 The present invention provides a fast-start random jitter delayed emission laser device, comprising: a piezoelectric ceramic total reflection mirror 1, a laser crystal 2, a total reflection mirror 3, an LD array side pump source 4, a right-angle prism 5, an acousto-optic modulator 6, a driving signal generator 7, a random jitter delay controller 8, and an output mirror 9.

[0011] The piezoelectric ceramic total reflection mirror 1, the total reflection mirror 3 and the right-angle prism 5 form a long pulse waiting L-type resonant cavity.

[0012] The piezoelectric ceramic total reflection mirror 1, the laser crystal 2, and the total reflection mirror 3 are placed from left to right in sequence.

[0013] The reflecting surface of the total reflection mirror 3 is set at 45° downward along the optical path, the acousto-optic modulator 6 and the right-angle prism 5 are placed in the reflecting optical path of the total reflection mirror 3 in sequence, the acousto-optic modulator 6 is located at the beam waist of the oscillating laser between the total reflection mirror 3 and the right-angle prism 5, the reflecting surface of the right-angle prism 5 faces the total reflection mirror 3, and the reflecting surface of the right-angle prism 5 is parallel to the reflecting surface of the total reflection mirror 3.

[0014] The LD array side pumping source 4 is placed on the side of the laser crystal 2 .

[0015] The driving signal generator 7 is electrically connected to the acousto-optic modulator 6 .

[0016] The random jitter delay controller 8 is electrically connected to the driving signal generator 7 , and the random jitter delay controller 8 presets a plurality of timing random numbers.

[0017] The output mirror 9 is located on the reflection light path of the total reflection mirror 3 , and the output mirror 9 is arranged at 45° along the light path to complete the laser emission.

[0018] In one embodiment, the laser crystal 2 is a Nd:YAG crystal.

[0019] In one embodiment, the output wavelength of the LD array side pump source 4 is 808 nm.

[0020] In one embodiment, the output mirror 9 is a plane mirror, and the piezoelectric ceramic total reflection mirror 1 and the total reflection mirror 3 are concave mirrors.

[0021] In one embodiment, the reflective surfaces of the output mirror 9 and the right-angle prism 5 are coated with a 1064nm total reflection film, and the piezoelectric ceramic total reflection mirror 1 and the total reflection mirror 3 are coated with 808nm and 1064nm total reflection films.

[0022] According to one aspect of the present invention, the present invention provides a method for quickly starting random jitter delayed emission laser output, comprising the following steps:

[0023] The LD array side pump source 4 emits 808nm pump light to side pump the laser crystal 2;

[0024] The laser crystal 2 absorbs the pump light to form a population inversion, and stimulated radiation occurs to generate a 1064nm laser, which forms a stable oscillation in the L-shaped resonant cavity.

[0025] Controlling the acousto-optic modulator 6 to change the intracavity loss, when the laser cannot be output, a long pulse laser is formed in the laser cavity to wait;

[0026] Changing the operating voltage of the acousto-optic modulator 6, using the cavity emptying technology to release all the laser energy stored in the cavity, and realizing instantaneous laser output;

[0027] Control the random jitter delay controller 8 to generate a trigger signal, randomly select a timing random number from the multiple timing random numbers as the time zero point of the driving signal generator 7, and since the timing random number has a negative value, the time zero point has jitter before and after the normal transmission pulse time;

[0028] When the time zero is reached, the driving signal generator 7 generates a strong ultrasonic field to act on the AOM 6. The laser beam is emitted to the outside of the cavity by the first-order diffraction of the AOM 6 and outputted through the output mirror 9 to realize cavity emptying.

[0029] Figure 2 As shown, Figure 2 (a) is a case where the random jitter delay controller 8 is not added, and the driving signal generator 7 directly controls the generation of pulsed laser output with a fixed repetition rate and pulse width, ignoring the different pulse widths caused by cavity emptying caused by piezoelectric ceramics. Figure 2 (b) Figure 2 (c) The random numbers preset for the random jitter delay controller 8 are different, resulting in different random jitter delays in the cavity emptying pulse output. The distance between the dotted line and the rising edge of the pulse (time zero) is the random jitter delay time (the delay time has a negative value, that is, the cavity emptying is achieved in advance), causing the laser output time to jitter around a fixed pulse laser.

[0030] (III) Beneficial effects

[0031] Compared with the prior art, the present invention provides a fast-start random jitter delayed laser emission device and output method, which has the following beneficial effects:

[0032] The fast-start random jitter delayed emission laser device proposed in the present invention, on the one hand, sets an acousto-optic modulator to realize cavity emptying and shorten the laser emission time to achieve fast start-up; on the other hand, it changes the laser emission time by changing the timing random number to achieve delay jitter, and by presetting n groups of timing random numbers in advance and changing the preset timing random numbers to output different pulse lasers, the anti-interference ability of the multi-channel laser radar is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a fast-start random jitter delay laser emission device;

[0034] Figure 2 The present invention is a schematic diagram of preset timing random numbers of a random jitter delay controller of a quick-start random jitter delay laser emission device.

[0035] In the figure: 1. Piezoelectric ceramic total reflection mirror; 2. Laser crystal; 3. Total reflection mirror; 4. LD array side pumping source; 5. Right-angle prism; 6. Acousto-optic modulator; 7. Driving signal generator; 8. Random jitter delay controller; 9. Output mirror. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example

[0038] like Figure 1-2 As shown, an embodiment of the present invention provides a fast start random jitter delay laser emission device, such as Figure 1 shown.

[0039] According to one aspect of the present invention, Figure 1 The present invention provides a fast-start random jitter delayed emission laser device, comprising: a piezoelectric ceramic total reflection mirror 1, a laser crystal 2, a total reflection mirror 3, an LD array side pump source 4, a right-angle prism 5, an acousto-optic modulator 6, a driving signal generator 7, a random jitter delay controller 8, and an output mirror 9.

[0040] The piezoelectric ceramic total reflection mirror 1, the total reflection mirror 3 and the right-angle prism 5 form a long pulse waiting L-type resonant cavity.

[0041] The piezoelectric ceramic total reflection mirror 1, the laser crystal 2, and the total reflection mirror 3 are placed from left to right in sequence.

[0042] The reflecting surface of the total reflection mirror 3 is set at 45° downward along the optical path, the acousto-optic modulator 6 and the right-angle prism 5 are placed in the reflecting optical path of the total reflection mirror 3 in sequence, the acousto-optic modulator 6 is located at the beam waist of the oscillating laser between the total reflection mirror 3 and the right-angle prism 5, the reflecting surface of the right-angle prism 5 faces the total reflection mirror 3, and the reflecting surface of the right-angle prism 5 is parallel to the reflecting surface of the total reflection mirror 3.

[0043] The LD array side pumping source 4 is placed on the side of the laser crystal 2 .

[0044] The driving signal generator 7 is electrically connected to the acousto-optic modulator 6 .

[0045] The random jitter delay controller 8 is electrically connected to the driving signal generator 7 , and the random jitter delay controller 8 presets a plurality of timing random numbers.

[0046] The output mirror 9 is located on the reflection light path of the total reflection mirror 3 , and the output mirror 9 is arranged at 45° along the light path to complete the laser emission.

[0047] In one embodiment, the laser crystal 2 is a Nd:YAG crystal.

[0048] In one embodiment, the output wavelength of the LD array side pump source 4 is 808 nm.

[0049] In one embodiment, the output mirror 9 is a plane mirror, and the piezoelectric ceramic total reflection mirror 1 and the total reflection mirror 3 are concave mirrors.

[0050] In one embodiment, the reflective surfaces of the output mirror 9 and the right-angle prism 5 are coated with a 1064nm total reflection film, and the piezoelectric ceramic total reflection mirror 1 and the total reflection mirror 3 are coated with 808nm and 1064nm total reflection films.

[0051] According to one aspect of the present invention, the present invention provides a method for quickly starting random jitter delayed emission laser output, comprising the following steps:

[0052] The LD array side pump source 4 emits 808nm pump light to side pump the laser crystal 2;

[0053] The laser crystal 2 absorbs the pump light to form a population inversion, and stimulated radiation occurs to generate a 1064nm laser, which forms a stable oscillation in the L-shaped resonant cavity.

[0054] Controlling the acousto-optic modulator 6 to change the intracavity loss, when the laser cannot be output, a long pulse laser is formed in the laser cavity to wait;

[0055] Changing the operating voltage of the acousto-optic modulator 6, using the cavity emptying technology to release all the laser energy stored in the cavity, and realizing instantaneous laser output;

[0056] Control the random jitter delay controller 8 to generate a trigger signal, randomly select a timing random number from the multiple timing random numbers as the time zero point of the driving signal generator 7, and since the timing random number has a negative value, the time zero point has jitter before and after the normal transmission pulse time;

[0057] When the time zero is reached, the driving signal generator 7 generates a strong ultrasonic field to act on the AOM 6. The laser beam is emitted to the outside of the cavity by the first-order diffraction of the AOM 6 and outputted through the output mirror 9 to realize cavity emptying.

[0058] Figure 2 As shown, Figure 2 (a) is a case where the random jitter delay controller 8 is not added, and the driving signal generator 7 directly controls the generation of pulsed laser output with a fixed repetition rate and pulse width, ignoring the different pulse widths caused by cavity emptying caused by piezoelectric ceramics. Figure 2 (b) Figure 2 (c) The random jitter delay controller 8 presets different timing random numbers, resulting in different random jitter delays in the cavity emptying pulse output. The distance between the dotted line and the pulse rising edge (time zero) is the random jitter delay time (the delay time has a negative value, that is, the cavity emptying is achieved in advance), so that the laser output time jitters around the fixed pulse laser. Preset n groups of timing random numbers in advance to output different pulse lasers, and achieve the anti-interference performance of the multi-channel laser radar.

[0059] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fast-start random jitter delayed laser emission device, characterized in that: include: Piezoelectric ceramic total reflection mirror, laser crystal, total reflection mirror, LD array side pump source, right-angle prism, acousto-optic modulator, drive signal generator, random jitter delay controller, output mirror; The piezoelectric ceramic total reflection mirror, the total reflection mirror and the right-angle prism form a long pulse waiting L-type resonant cavity; The piezoelectric ceramic total reflection mirror, the laser crystal, and the total reflection mirror are placed from left to right in sequence; The reflecting surface of the total reflection mirror is arranged at 45 degrees downward along the optical path, the acousto-optic modulator and the right-angle prism are sequentially placed on the reflecting optical path of the total reflection mirror, the acousto-optic modulator is located at the beam waist of the oscillating laser between the total reflection mirror and the right-angle prism, the reflecting surface of the right-angle prism faces the total reflection mirror, and the reflecting surface of the right-angle prism is parallel to the reflecting surface of the total reflection mirror; The LD array side pumping source is placed on the side of the laser crystal; The driving signal generator is electrically connected to the acousto-optic modulator; The random jitter delay controller is electrically connected to the driving signal generator, and the random jitter delay controller presets a plurality of timing random numbers; The output mirror is located on the reflection light path of the total reflection mirror, and the output mirror is arranged at 45 degrees along the light path to complete the laser emission.

2. The fast-start random jitter delayed emission laser device according to claim 1, characterized in that: The laser crystal is a Nd:YAG crystal.

3. The fast start random jitter delayed emission laser device according to claim 1, characterized in that: The output wavelength of the LD array side pump source is 808 nm.

4. The fast-start random jitter delayed emission laser device according to claim 2, characterized in that: The output mirror is a plane mirror, and the piezoelectric ceramic total reflection mirror and the total reflection mirror are concave mirrors.

5. The fast-start random jitter delayed emission laser device according to claim 4, characterized in that: The output mirror and the reflecting surface of the right-angle prism are coated with a 1064nm total reflection film, and the piezoelectric ceramic total reflection mirror and the total reflection mirror are coated with 808nm and 1064nm total reflection films.

6. An output method of a fast-start random jitter delayed emission laser device, using the fast-start random jitter delayed emission laser device as claimed in any one of claims 1 to 5, comprising: S1, the LD array side pumping source emits 808nm pumping light to side pump the laser crystal; S2, the laser crystal absorbs the pump light to form a population inversion, and stimulated emission occurs, generating a 1064nm laser, and the 1064nm laser forms a stable oscillation in the L-type resonant cavity; S3, controlling the acousto-optic modulator to change the intracavity loss, and when the laser cannot be output, a long pulse laser is formed in the laser cavity to wait; S4, changing the operating voltage of the acousto-optic modulator, using the cavity emptying technology to release all the laser energy stored in the cavity, and realizing instantaneous laser output; S5, controlling the random jitter delay controller to generate a trigger signal, randomly selecting a timing random number from the multiple timing random numbers as the time zero point of the driving signal generator, and since the timing random number has a negative value, the time zero point has jitter before and after the normal transmission pulse time; S6. When the time zero is reached, the driving signal generator generates a strong ultrasonic field to act on the AOM. The laser beam is emitted to the outside of the cavity by the first-order diffraction of the AOM and outputted through the output mirror to realize cavity emptying.

Images