Laser emission module and lidar

Abstract

The present invention relates to the field of laser radar detection technology, and more specifically, to a laser emission module and a laser radar. The laser emission module includes a housing, within which is disposed a transmission channel, a beam combiner, and a first extinction structure. The first extinction structure includes a first optical trap recessed in the wall of the transmission channel; the beam combiner is mounted in a notch in the first optical trap. The laser radar includes the aforementioned laser emission module. The laser emission module and laser radar provided by the present invention have low stray light within the channel, thereby preventing stray light from interfering with the laser radar's detection of the distance and shape of the detected object, thereby improving the laser radar's detection accuracy.

Description

Technical Field

[0001] The present invention relates to the field of laser radar detection technology, and in particular to a laser emission module and a laser radar. Background Art

[0002] With the development of technology, laser radar has been widely used due to its advantages such as high resolution, strong anti-interference ability and small size. The main light source of laser radar is semiconductor laser. The laser it emits has a certain angle and the energy is relatively divergent. Generally, the light beam is adjusted through a lens to make the emitted light beam into a collimated state. At this time, the light beam energy is strong and the detector can detect the light returned from distant targets.

[0003] Components such as lasers, lenses, and detectors generally need to be installed in a housing, which is used to fix these components. During laser propagation, the housing will block part of the divergent light beam, causing part of the divergent light to reflect back and forth inside the housing. The reflected part of the divergent light will be reflected on the detector inside the housing, resulting in the detector receiving not only the light reflected from the target object, but also stray light reflected from the inner wall of the housing and the edge of the optical device. These stray lights will interfere with the laser radar's detection of the distance and shape of the detected object, affecting the laser radar's detection accuracy.

[0004] In summary, how to overcome the above-mentioned defects of existing lidar is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser emission module and a laser radar to alleviate the technical problem of low detection accuracy existing in the laser radar in the prior art.

[0006] The laser emission module provided by the present invention includes a shell, in which an emission channel, a beam combining mirror and a first extinction structure are provided. The first extinction structure includes a first optical trap, and the first optical trap is recessed in the channel wall of the emission channel; the beam combining mirror is installed in the notch of the first optical trap.

[0007] Preferably, as an implementation method, the laser emission module also includes a second extinction structure, the second extinction structure includes a second optical trap, the second optical trap is recessed in the channel wall of the emission channel, and is located close to the beam combiner, and the second optical trap can absorb stray light emitted through the beam combiner along the propagation direction of the light.

[0008] The first optical trap can absorb stray light emitted from the side of the beam combiner.

[0009] Preferably, as an implementation method, the channel wall of the emission channel has a first inclined surface, and the first inclined surface is inclined along the propagation direction of the light in the direction away from the light, and a protruding light-blocking strip is provided on the first inclined surface, and the first inclined surface and the light-blocking strip form the second optical trap.

[0010] Preferably, as an implementable embodiment, the laser emission module also includes a third extinction structure, and the third extinction structure includes a first extinction channel and a third optical trap connected to the emission channel; the entrance opening size of the first extinction channel is smaller than the exit opening size, and gradually and smoothly transitions from the entrance opening part to the exit opening part.

[0011] The third optical trap is located at the outlet opening side of the first extinction channel, and the third optical trap is recessed into the channel wall of the first extinction channel.

[0012] Preferably, as an implementable embodiment, the channel wall of the first extinction channel has a plurality of second inclined surfaces, and the second inclined surfaces gradually and smoothly transition from the entrance opening portion to the exit opening portion of the first extinction channel; the third optical trap is arranged on the second inclined surface and is recessed in the second inclined surface.

[0013] Preferably, as an implementation method, the channel wall of the first extinction channel has two second inclined surfaces, which are arranged opposite to each other.

[0014] Preferably, as an implementable embodiment, the third extinction structure also includes a fourth optical trap, and the fourth optical trap is arranged on the entrance opening side of the first extinction channel. The entrance opening size of the first extinction channel is smaller than the opening size of the emission channel on the entrance side, and the fourth optical trap is recessed in the channel wall of the emission channel.

[0015] Preferably, as an implementable embodiment, the laser emission module also includes a laser, a first lens group, a second lens group and a semi-transparent and semi-reflective mirror, and the laser, the first lens group, the third extinction structure, the second lens group, the beam combiner and the semi-transparent and semi-reflective mirror are arranged in sequence along the direction of light propagation.

[0016] Correspondingly, the present invention also provides a laser radar, which includes the above-mentioned laser emission module.

[0017] Preferably, as an implementable embodiment, the laser radar further includes a laser receiving module, and the laser receiving module includes a receiving channel and a fourth extinction structure provided in the shell.

[0018] The fourth extinction structure includes a second extinction channel and a fifth optical trap connected to the receiving channel; the entrance opening size of the second extinction channel is smaller than the exit opening size, and gradually and smoothly transitions from the entrance opening to the exit opening; the fifth optical trap is arranged at the exit opening of the second extinction channel and is recessed in the channel wall of the second extinction channel.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The laser emission module provided by the present invention comprises a housing, within which are disposed an emission channel for laser light and a beam combiner. After a laser emits laser light into the emission channel within the housing, the laser light is emitted along the emission channel through the beam combiner and then onto the object being detected. The beam combiner compresses the spot size of the beam, thereby reducing the optical parameter product and improving beam quality.

[0021] Because of the light beam of the beam combiner, some light will be emitted as stray light when passing through the beam combiner. The present invention adds a first extinction structure in the emission channel of the shell, and the first extinction structure includes a first optical trap. The first optical trap is set to be recessed in the channel wall of the emission channel. Therefore, after the above-mentioned stray light is emitted by the beam combiner, it will be emitted into the first optical trap recessed in the channel wall of the emission channel through the notch of the first optical trap and absorbed by the first optical trap. Therefore, this part of the stray light will not continue to propagate along the emission channel.

[0022] Therefore, the laser emission module provided by the present invention has less stray light in the emission channel, so that the stray light is less likely to interfere with the laser radar's detection of the distance and shape of the detected object, thereby improving the detection accuracy of the laser radar.

[0023] The laser radar provided by the present invention includes the above-mentioned laser emission module, so there is less stray light in the emission channel and the detection accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A three-dimensional diagram of a partial structure of a laser radar provided in an embodiment of the present invention;

[0026] Figure 2 A front view of a partial structure of a laser radar provided by an embodiment of the present invention;

[0027] Figure 3 A schematic structural diagram of a beam combiner in a laser emission module provided by an embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of a first extinction structure in a laser emission module provided in an embodiment of the present invention;

[0029] Figure 5 A schematic structural diagram of a second extinction structure in a laser emission module provided in an embodiment of the present invention;

[0030] Figure 6 A schematic structural diagram of a third extinction structure in a laser emission module provided in an embodiment of the present invention;

[0031] Figure 7 A schematic structural diagram of a fourth extinction structure of a laser receiving module in a laser radar provided in an embodiment of the present invention;

[0032] Figure 8 A schematic structural diagram of the fifth extinction structure of the laser receiving module in the laser radar provided in an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 110-transmitting channel; 120-receiving channel;

[0035] 200- beam combiner; 210- polarizing film;

[0036] 300 - first extinction structure; 310 - first optical trap; 311 - first side wall; 312 - second side wall; 313 - third side wall; 314 - notch;

[0037] 400-second matte structure; 410-first inclined surface; 420-light-blocking strip;

[0038] 500 - third extinction structure; 510 - first extinction channel; 511 - second inclined surface; 520 - third optical trap; 530 - fourth optical trap;

[0039] 600 - fourth extinction structure; 610 - second extinction channel; 611 - third inclined surface; 620 - fifth optical trap; 630 - sixth optical trap;

[0040] 700-fifth extinction structure; 710-third extinction channel; 711-fourth inclined surface;

[0041] 810 - first lens group; 820 - second lens group; 830 - semi-transparent and semi-reflective mirror; 840 - third lens group; 841 - first lens; 842 - second lens; 850 - fourth lens group; 860 - reflective mirror. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] The present invention will be further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0044] See also Figures 1-4 This embodiment provides a laser emission module, which includes a shell, in which an emission channel 110, a beam combiner 200 and a first extinction structure 300 are provided. The first extinction structure 300 includes a first optical trap 310, and the first optical trap 310 is recessed in the channel wall of the emission channel 110; the beam combiner 200 is installed at the notch 314 of the first optical trap 310.

[0045] In the laser emission module provided in this embodiment, the laser emits laser light into the emission channel 110 within the housing. The laser light then passes through the beam combiner 200 along the emission channel 110 and exits, striking the object being detected. The beam combiner 200 compresses the spot size of the beam, thereby reducing the optical parameter product and improving beam quality.

[0046] Because of the light beam of the beam combiner 200, some light will be emitted as stray light when passing through the beam combiner 200. After being emitted through the beam combiner 200, this part of the stray light will be emitted into the first optical trap 310 recessed in the channel wall of the emission channel 110 through the notch 314 of the first optical trap 310 and absorbed by the first optical trap 310. As a result, this part of the stray light will not continue to propagate along the emission channel 110.

[0047] Therefore, the laser emission module provided in this embodiment has less stray light in the emission channel 110, so that the stray light is less likely to interfere with the laser radar's detection of the distance and shape of the detection object, which can improve the detection accuracy of the laser radar.

[0048] Specifically, the first optical trap 310 can absorb the stray light emitted from the side of the beam combiner 200, preventing this part of the light from continuing to propagate in the emission channel 110, thereby reducing the stray light in the emission channel 110. In fact, the side of the beam combiner 200 is along the propagation direction of the light (i.e., the propagation direction of the main light, see Figure 2 The direction indicated by the arrow in the figure is parallel or nearly parallel to the direction of light propagation.

[0049] In practice, the beam combiner 200 in this embodiment is provided with a polarizing film 210. A half-wave plate is attached to one side of the polarizing film 210 on the light incident side of the beam combiner 200. Accordingly, the portion of the beam combiner 200 on the other side of the polarizing film 210 is mounted to the notch 314 of the first optical trap 310. Based on this structure, stray light emitted from the side of the beam combiner 200 can enter the first optical trap 310 through the notch 314 of the first optical trap 310, thereby absorbing the stray light emitted from the side of the beam combiner 200. Of course, other types of beam combiners 200 may also be used, and will not be described in detail here.

[0050] See also Figure 4 The first optical trap 310 may specifically comprise a polygonal prism groove. The notch 314 of the first optical trap 310 is formed on the sidewall of the polygonal prism groove. In this manner, stray light emitted from the side of the beam combiner 200 can enter the polygonal prism groove through the notch 314 on the sidewall of the polygonal prism groove. The light entering the polygonal prism groove is reflected and absorbed by the groove walls, achieving the purpose of light extinction. Within the polygonal prism groove, the light is primarily reflected and absorbed by the sidewalls.

[0051] Specifically, the polygonal prism groove has at least a first side wall 311, a second side wall 312 and a third side wall 313. The first side wall 311 and the second side wall 312 are arranged opposite to each other, and the first side wall 311 and the second side wall 312 are arranged to be parallel to each other. The angle between the first side wall 311 and the polarizing film 210 in the beam combiner 200 is set to 45°, that is, the light passing through the reflective side of the interface 210 in the beam combiner 200 is nearly parallel to the first side wall 311 of the polygonal prism groove; the third side wall 313 is set to 45°. The side wall 313 is arranged opposite to the notch 314 of the polygonal prism groove, and the angle range between the third side wall 313 and the first side wall 311 is set to 40° to 60°. In this way, the light entering from the notch 314 of the polygonal prism groove can hit the third side wall 313 and be reflected by the third side wall 313 to the first side wall 311 or the second side wall 312, and then be reflected again by the first side wall 311 or the second side wall 312 to the other side wall. In this way, the extinction purpose of the polygonal prism groove can be achieved.

[0052] Further, see Figure 2A second extinction structure 400 may also be added. The second extinction structure 400 includes a second optical trap. The second optical trap is set to be recessed in the channel wall of the emission channel 110, and the second optical trap is set near the beam combiner 200. The stray light emitted along the light propagation direction through the beam combiner 200 can enter the second optical trap. The second optical trap can absorb this part of the divergent light, thereby preventing this part of the light from continuing to propagate along the emission channel 110, further reducing the stray light in the emission channel 110. In fact, the stray light emitted along the light propagation direction through the beam combiner 200 is the stray light emitted from the side of the beam combiner 200 that emits most of the light (hereinafter referred to as the main light emitting side of the beam combiner 200). Obviously, this part of the stray light is located on the main light emitting side of the beam combiner 200. Therefore, the second optical trap is also located on the main light emitting side of the beam combiner 200.

[0053] Specifically, see Figure 2 and Figure 5 A first inclined surface 410 can be provided on the channel wall of the emission channel 110, and the first inclined surface 410 is tilted in the direction away from the light along the propagation direction of the light, and a protruding light-blocking strip 420 is provided on the first inclined surface 410. At this time, the light-blocking strip 420 and the first inclined surface 410 can form the above-mentioned second optical trap. The stray light emitted along the propagation direction of the light through the beam combiner 200 can hit the light-blocking strip 420 along the first inclined surface 410 and be reflected by the light-blocking strip 420, thereby preventing this part of the light from continuing to propagate along the emission channel 110, further reducing the stray light.

[0054] Specifically, the angle between the first inclined surface 410 and the direction of light propagation can be set to 45°, and the angle between the light blocking strip 420 and the first inclined surface 410 can be set to 50°~70°, so that the divergent light emitted from the main light emitting side of the combiner 200 can smoothly hit the light blocking strip 420 along the first inclined surface 410.

[0055] See also Figure 2 and Figure 6In the laser emission module provided in this embodiment, a third extinction structure 500 may be further provided. The third extinction structure 500 includes a first extinction channel 510 and a third optical trap 520. The first extinction channel 510 is connected to the emission channel 110. The entrance opening size of the first extinction channel 510 is smaller than the exit opening size, and the first extinction channel 510 gradually and smoothly transitions from the entrance opening to the exit opening. The third optical trap 520 is located on the exit opening side of the first extinction channel 510, and the third optical trap 520 is recessed in the channel wall of the first extinction channel 510. The entrance opening of the first extinction channel 510 is the opening of the first extinction channel 510 for laser incidence, and the exit opening of the first extinction channel 510 is the opening of the first extinction channel 510 for laser emission.

[0056] The stray light that enters the first extinction channel 510 from the entrance of the first extinction channel 510 will propagate along the channel wall of the first extinction channel 510 toward the exit of the first extinction channel 510. After being emitted from the exit of the first extinction channel 510, this part of the stray light will enter the third optical trap 520 located on the exit side of the first extinction channel 510. The energy of the stray light that enters the third optical trap 520 can be absorbed by the third optical trap 520. Therefore, this part of the stray light will not continue to propagate along the emission channel 110, thereby reducing the stray light in the emission channel 110.

[0057] It should be noted that the cross-sectional shape of the first extinction channel 510 can be circular, rectangular or other shapes. When it is circular, the opening size of the first extinction channel 510 (including the inlet opening size and the outlet opening size) is the opening diameter; when it is rectangular, the opening size of the first extinction channel 510 (including the inlet opening size and the outlet opening size) is the opening length and width size; in fact, the first extinction channel 510 can form a trumpet-shaped structure or a trumpet-shaped structure.

[0058] Specifically, the channel wall of the first extinction channel 510 has a plurality of second inclined surfaces 511, which gradually and smoothly transition from the entrance opening of the first extinction channel 510 to the exit opening. The third optical trap 520 is set on the second inclined surface 511 and is recessed in the second inclined surface 511. In this way, stray light entering the first extinction channel 510 from the entrance of the first extinction channel 510 can propagate along the second inclined surface 511 toward the exit of the first extinction channel 510 and enter the third optical trap 520 recessed in the second inclined surface 511. As a result, the third optical trap 520 can absorb part of the stray light and reduce the stray light propagating to the detector.

[0059] Preferably, the second inclined surfaces 511 can be two, that is, the channel wall of the first matte channel 510 has two second inclined surfaces 511 , and the two second inclined surfaces 511 are arranged opposite to each other. In this way, not only a better matte effect can be achieved, but also processing is facilitated.

[0060] The included angle between the two first inclined surfaces 511 may be set to range from 20° to 140°, and the specific included angle value may be set according to actual needs.

[0061] In the specific structure of the above-mentioned third extinction structure 500, a fourth optical trap 530 can also be set. The fourth optical trap 530 is set on the entrance opening side of the first extinction channel 510, and the entrance opening size of the first extinction channel 510 is set to be smaller than the passage size of the emission channel 110 on the entrance side. The above-mentioned fourth optical trap 530 is recessed in the channel wall of the emission channel 110. In this way, the fourth optical trap 530 can preliminarily absorb the divergent light entering the emission channel 110, and the fourth optical trap 530 can also absorb the divergent light reflected by the entrance side end face of the first extinction channel 510, which can further reduce the stray light in the emission channel 110.

[0062] The first extinction channel 510 can be configured as either of the following two structures:

[0063] The first one is to provide a protruding structure on the shell that protrudes toward the inside of the emission channel 110, and utilize the protruding structure as the first extinction channel 510. In this way, the number of parts can be reduced and the assembly efficiency can be improved.

[0064] The second method is to open a slot on the shell and add a part with the above-mentioned first extinction channel 510, and plug the part into the slot. Since the part is an independent structure, the shape requirements of the first extinction channel 510 are relatively low, and the shape of the first extinction channel 510 can be freely selected according to actual needs.

[0065] A plurality of arcuate grooves may be provided in the specific structures of the third optical trap 520 and the fourth optical trap 530. The shape of the longitudinal cross-section of the arcuate groove is set to an arc, so that the arcuate grooves in the third optical trap 520 correspond one-to-one with the second inclined surface 511, and the arcuate grooves in the fourth optical trap 530 also correspond one-to-one with the second inclined surface 511. In this way, the divergent light will enter the arcuate groove corresponding to the second inclined surface 511 of the third optical trap 520 along the second inclined surface 511, or be reflected by the connecting end surface of the channel wall and the entrance side of the second inclined surface 511 into the arcuate groove corresponding to the second inclined surface 511 of the fourth optical trap 530, and can be reflected back and forth in the arcuate groove to achieve the purpose of extinction.

[0066] Preferably, any one of the first optical trap 310 , the second optical trap, the third optical trap 520 , and the fourth optical trap 530 may be coated with a light-absorbing material or affixed with a light-absorbing film to improve the extinction effect.

[0067] The number of the aforementioned first extinction channels 510 can be set as needed, that is, one or more first extinction channels 510 can be provided, with multiple first extinction channels 510 arranged sequentially along the light propagation direction, and the arrangement order can be set as needed. When there are two or more first extinction channels 510, it is preferred to dispose a fourth optical trap 530 on the entrance opening side of the first extinction channel 510 closest to the laser entrance port of the housing, and a third optical trap 520 between any two adjacent first extinction channels 510. In this case, the third optical trap 520 can also function as the fourth optical trap 530 relative to the first extinction channel 510 located on its exit side. This not only simplifies the structure, but also improves the compactness of the extinction structure and enhances the extinction effect.

[0068] The number of the third matt structures 500 can be set as needed, that is, the third matt structure 500 can be set to one or more, and several third matt structures 500 are arranged in sequence along the light propagation direction, and the arrangement order can be set as needed.

[0069] See also Figure 2 The laser emission module provided in this embodiment also includes a laser, a first lens group 810, a second lens group 820, and a semi-transparent and semi-reflective mirror 830. The laser, the first lens group 810, the third extinction structure 500, the second lens group 820, the beam combiner 200, and the semi-transparent and semi-reflective mirror 830 are arranged in sequence along the direction of light propagation. In this way, the laser emitted by the laser can pass through the first lens group 810, the third extinction structure 500, the second lens group 820, the beam combiner 200, and the semi-transparent and semi-reflective mirror 830 in sequence along the emission channel 110 and then hit the detection object. Specifically, the laser is installed in the housing and is located outside the emission channel 110. The first lens group 810, the third extinction structure 500, the second lens group 820, the beam combiner 200, and the semi-transparent and semi-reflective mirror 830 are all installed inside the emission channel 110.

[0070] See also Figure 1 and Figure 2 , this embodiment also provides a laser radar, which includes the above-mentioned laser emission module.

[0071] Therefore, the laser radar provided in this embodiment has less stray light in the transmission channel 110 and higher detection accuracy.

[0072] Specifically, see Figure 2 and Figure 7The laser radar provided in this embodiment also includes a laser receiving module, which includes a receiving channel 120 and a fourth extinction structure 600 disposed within the aforementioned housing. The fourth extinction structure 600 includes a second extinction channel 610 and a fifth optical trap 620, which are connected to the receiving channel 120. The entrance opening of the second extinction channel 610 is smaller than the exit opening, and the entrance opening gradually and smoothly transitions to the exit opening. The fifth optical trap 620 is disposed at the exit opening of the second extinction channel 610 and is recessed into the channel wall of the second extinction channel 610. The entrance opening of the second extinction channel 610 is the opening through which laser light enters the second extinction channel 610, and the exit opening of the second extinction channel 610 is the opening through which laser light exits the second extinction channel 610.

[0073] After the laser beam reflected by the detected object enters the receiving channel 120 in the shell, it can propagate along the receiving channel 120 until it is detected and received by the detector. Since the entrance opening size of the second extinction channel 610 is smaller than the exit opening size, and the second extinction channel 610 gradually and smoothly transitions from the entrance opening to the exit opening, the stray light entering the second extinction channel 610 from the entrance of the second extinction channel 610 will propagate along the channel wall of the second extinction channel 610 toward the exit of the second extinction channel 610 and enter the fifth optical trap 620 that is recessed and located on the exit side of the second extinction channel 610. The energy of the stray light entering the fifth optical trap 620 can be absorbed by the fifth optical trap 620, so that this part of the stray light will not continue to propagate along the receiving channel 120, thereby reducing the stray light detected by the detector and further improving the detection accuracy.

[0074] The second extinction channel 610 can be configured to have a structure similar to the first extinction channel 510 , and the fifth optical trap 620 can be configured to have a structure similar to the third optical trap 520 .

[0075] Specifically, the channel wall of the second extinction channel 610 has a plurality of third inclined surfaces 611, which gradually and smoothly transition from the entrance opening of the second extinction channel 610 to the exit opening. The fifth optical trap 620 is set on the third inclined surface 611 and is recessed in the third inclined surface 611. In this way, stray light entering the second extinction channel 610 from the entrance of the second extinction channel 610 can propagate along the third inclined surface 611 toward the exit of the second extinction channel 610 and enter the fifth optical trap 620 recessed in the third inclined surface 611. As a result, the fifth optical trap 620 can absorb part of the stray light and reduce the stray light propagating to the detector.

[0076] Preferably, the third inclined surface 611 can be set to two, that is, the channel wall of the second matte channel 610 has two third inclined surfaces 611, and the two third inclined surfaces 611 are arranged opposite to each other. In this way, not only a better matte effect can be achieved, but also processing is facilitated.

[0077] The included angle between the two third inclined surfaces 611 may be set to range from 20° to 100°, and the specific included angle value may be set according to actual needs.

[0078] The entrance opening size of the second extinction channel 610 is set to be smaller than the channel opening size of the receiving channel 120 on the entrance side, and a sixth optical trap 630 is formed from the entrance opening of the second extinction channel 610 to the channel wall of the receiving channel 120 on the entrance side. The sixth optical trap 630 is used to perform preliminary absorption of stray light entering the receiving channel 120, which can further reduce the stray light propagating to the detector.

[0079] Preferably, the fifth optical trap 620 and the sixth optical trap 630 may be coated with a light-absorbing material or affixed with a light-absorbing film to improve the extinction effect.

[0080] See also Figure 2 and Figure 8 A fifth extinction structure 700 may also be provided within the housing. The fifth extinction structure 700 includes a third extinction channel 710 connected to the aforementioned receiving channel 120. The entrance opening of the third extinction channel 710 is configured to be smaller than the exit opening, and the third extinction channel 710 transitions smoothly from the entrance opening to the exit opening. Therefore, stray light entering the third extinction channel 710 from the entrance will propagate along the channel wall of the third extinction channel 710 toward the exit. This means that the propagation direction of the stray light will deviate from the main propagation direction of the laser beam, thereby reducing stray light reaching the detector. The entrance opening of the third extinction channel 710 is the opening through which the laser beam enters the third extinction channel 710, and the exit opening of the third extinction channel 710 is the opening through which the laser beam exits the third extinction channel 710.

[0081] In fact, part of the stray light entering the third extinction channel 710 will be reflected by the channel wall of the third extinction channel 710 to the surrounding structure and reflected by the surrounding structure, and another part will directly hit the surrounding structure and be reflected by the surrounding structure to the channel wall of the third extinction channel 710. After several reflections, this part of the stray light will disappear. Therefore, the extinction effect of the third extinction channel 710 can be improved, and the stray light propagating to the detector can be further reduced.

[0082] The third extinction channel 710 may be configured to have a structure similar to the second extinction channel 610 described above.

[0083] Specifically, the channel wall of the third extinction channel 710 has a plurality of fourth inclined surfaces 711, which gradually and smoothly transition from the entrance opening of the third extinction channel 810 to the exit opening. In this way, the stray light entering the third extinction channel 810 can propagate along the fourth inclined surfaces 711 in a direction deviating from the main propagation direction of the laser beam.

[0084] Preferably, the fourth inclined surface 711 can be set to two, that is, the channel wall of the third extinction channel 810 has two fourth inclined surfaces 711, and the two fourth inclined surfaces 711 are arranged opposite to each other. In this way, not only a better extinction effect can be achieved, but also processing is convenient.

[0085] Specifically, the included angle between the two fourth inclined surfaces 711 can be set to range from 30° to 80°, and the specific included angle value can be set according to actual needs.

[0086] The number of the fourth matte structure 600 and the fifth matte structure 700 can be set as needed, that is, the fourth matte structure 600 can be set to one or more, and the fifth matte structure 700 can also be set to one or more. Several fourth matte structures 600 and several fifth matte structures 700 are arranged in sequence along the direction of light propagation, and the arrangement order can be set as needed.

[0087] See also Figure 2 The laser emission module provided in this embodiment also includes a third lens group 840 and a fourth lens group 850 located in the receiving channel 120. The third lens group 840, the fourth extinction structure 600, the fourth lens group 850 and the fifth extinction structure 700 are arranged in sequence along the light propagation direction. In this way, the light reflected back to the receiving channel 120 by the detected object can pass through the third lens group 840, the fourth extinction structure 600, the fourth lens group 850 and the fifth extinction structure 700 in sequence along the receiving channel 120, and is finally received by the detector.

[0088] The third lens group 840 may include two lenses, which are sequentially spaced apart along the light propagation direction. Figure 2As shown, along the direction of light propagation, the two lenses are respectively a first lens 841 and a second lens 842, and the two lenses are set at an angle, for example, vertically (other angles are also possible), and a reflector 860 is set between the first lens 841 and the second lens 842. In this way, the laser passing through the first lens 841 is incident on the reflector 860 and then changes direction to be incident on the second lens 832, so as to effectively change the direction of light propagation, thereby shortening the geometric length of the laser receiving module, facilitating the compact design of the laser receiving module and even the entire lidar system. Of course, in addition to this, the third lens group 840 can also be set into other structural forms. For example, the third lens group 840 includes a plurality of first lenses 841 or second lenses 842. When there is more than one lens, they can be set in parallel, which is not limited here.

[0089] It should be noted that, in this embodiment, the first lens group 810, the second lens group 820, and the fourth lens group 850 are all configured with one lens as an example. In addition, other structural forms can also be configured, for example, multiple lenses are arranged at intervals, multiple lenses are arranged at an angle, and in this case, a reflector 860 can be set between adjacent lenses. Of course, multiple lenses can also be arranged in parallel, which is not limited here.

[0090] In summary, the embodiments of the present invention disclose a laser emission module and lidar that overcome many technical drawbacks of conventional lidars. The laser emission module and lidar provided by the embodiments of the present invention have low stray light within the channel, which prevents stray light from interfering with the lidar's ability to detect the distance and shape of an object, resulting in higher detection accuracy.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser emission module, characterized in that: The invention comprises a shell, wherein an emission channel (110), a beam combining mirror (200) and a first extinction structure (300) are provided in the shell, wherein the first extinction structure (300) comprises a first optical trap (310), and the first optical trap (310) is recessed in the channel wall of the emission channel (110); the beam combining mirror (200) is installed at a notch (314) of the first optical trap (310); the first optical trap (310) comprises a polygonal prism groove, and the notch (314) of the first optical trap (310) is opened on the side wall of the polygonal prism groove; The laser emission module further comprises a second extinction structure (400), the second extinction structure (400) comprising a second optical trap, the second optical trap being recessed in a channel wall of the emission channel (110) and located near the beam combiner (200), the second optical trap being capable of absorbing stray light emitted along a light propagation direction through the beam combiner (200); The first optical trap (310) is capable of absorbing stray light emitted from the side of the beam combiner (200); The channel wall of the emission channel (110) has a first inclined surface (410), and the first inclined surface (410) is inclined in a direction away from the light along the propagation direction of the light, and a protruding light-blocking strip (420) is provided on the first inclined surface (410), and the first inclined surface (410) and the light-blocking strip (420) form the second optical trap.

2. The laser emission module according to claim 1, characterized in that: The laser emission module further comprises a third extinction structure (500), the third extinction structure (500) comprising a first extinction channel (510) in communication with the emission channel (110) and a third optical trap (520); the inlet opening size of the first extinction channel (510) is smaller than the outlet opening size, and the inlet opening portion gradually and smoothly transitions to the outlet opening portion; The third optical trap (520) is located at the outlet opening side of the first extinction channel (510), and the third optical trap (520) is recessed into the channel wall of the first extinction channel (510).

3. The laser emission module according to claim 2, characterized in that: The channel wall of the first extinction channel (510) has a plurality of second inclined surfaces (511), and the second inclined surfaces (511) gradually and smoothly transition from the entrance opening portion of the first extinction channel (510) to the exit opening portion; the third optical trap (520) is arranged on the second inclined surface (511) and is recessed in the second inclined surface (511).

4. The laser emission module according to claim 3, characterized in that: The channel wall of the first extinction channel (510) has two second inclined surfaces (511) which are arranged opposite to each other.

5. The laser emission module according to claim 3, characterized in that: The third extinction structure (500) further includes a fourth optical trap (530), which is arranged on the entrance opening side of the first extinction channel (510), the entrance opening size of the first extinction channel (510) being smaller than the entrance size of the emission channel (110) on the entrance side, and the fourth optical trap (530) is recessed in the channel wall of the emission channel (110).

6. The laser emission module according to claim 3, characterized in that: The laser emission module further comprises a laser, a first lens group (810), a second lens group (820) and a semi-transparent and semi-reflective mirror (830), wherein the laser, the first lens group (810), the third extinction structure (500), the second lens group (820), the beam combining mirror (200) and the semi-transparent and semi-reflective mirror (830) are sequentially arranged along the light propagation direction.

7. A laser radar, characterized in that: A laser emission module comprising the laser emission module according to any one of claims 1 to 6.

8. The laser radar according to claim 7, characterized in that The laser radar further comprises a laser receiving module, wherein the laser receiving module comprises a receiving channel (120) and a fourth extinction structure (600) provided in the housing; The fourth extinction structure (600) includes a second extinction channel (610) and a fifth optical trap (620) connected to the receiving channel (120); the inlet opening size of the second extinction channel (610) is smaller than the outlet opening size, and the inlet opening portion gradually and smoothly transitions to the outlet opening portion; the fifth optical trap (620) is arranged at the outlet opening portion of the second extinction channel (610) and is recessed in the channel wall of the second extinction channel (610).

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