Detection device and laser radar
By adjusting the positions of the light source components and polarization spectroscopy elements, the initial polarized light meets the polarization spectroscopy requirements, eliminating the modulation device, solving the problem of low transmission and reception efficiency of the lidar detection device, and achieving more efficient light energy utilization and longer detection distance.
Patent Information
- Application Number
- CN202323577044.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-26
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2033-12-26
AI Technical Summary
The existing lidar detection devices have low transmission and reception efficiency, resulting in limited effective detection distance, and the use of modulation devices leads to light energy loss.
By adjusting the relative positions of the light source assembly and the polarization spectroscopic element, the polarization direction of the initial polarization light is parallel to the front of the first region of the polarization spectroscopic element, the modulation device is eliminated, the light energy loss is reduced, and the transmission and reception efficiency of the lidar is improved.
It improves the transmission and reception efficiency of lidar, reduces the difficulty and cost of installation and adjustment, and extends the effective detection distance.
Smart Images
Figure CN222280826U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of optical systems, and more specifically, to a detection device, and also to a laser radar comprising the detection device. Background Art
[0002] At present, in the optical scheme of LiDAR, the transceiver scheme can be divided into two schemes: coaxial and off-axis. For the coaxial scheme, a spectrometer is needed to separate the return light from the outgoing light, but the spectrometer will lose part of the outgoing light energy and the return light energy. The optical efficiency of the spectrometer directly affects the transceiver optical efficiency of the LiDAR, thereby affecting its effective detection distance. The Chinese patent with publication number CN217543377U proposes a detection device that reduces the energy loss of receiving the return light by using a modulation device and a polarization spectrometer.
[0003] Figure 1 The optical path schematic diagram of an existing detection device is a schematic diagram of the optical path of the above detection device. The light source component 101 emits a P polarized light 102 with a polarization direction 109 polarized along the z-axis. The P polarized light 102 is converted into an S polarized light 104 with a polarization direction along the x-axis through a modulator 103. The polarized light 104 is incident on the central area of the polarization beam splitter 105 and is reflected by the central area to the target object 106. The reflected and scattered light 107 of the target object 106 will be incident on the central area and the peripheral area of the polarization beam splitter 105 again. If the light incident on the central area is a P polarized light 111 with a polarization direction polarized along the y-axis, it will be transmitted by the central area and received by the receiving component 108. The light incident on the peripheral area will be transmitted by the peripheral area regardless of the polarization direction of the light incident, and will be received by the receiving component 108. The modulator 103 is introduced into the detection device to change the polarization direction of the polarized light 102 emitted by the light source component 101. Since the modulator has a certain transmittance, it will cause the loss of emission energy and affect the detection performance.
[0004] In summary, how to effectively solve the problem of low transmission and reception efficiency of current detection devices is an issue that those skilled in the art urgently need to solve. Utility Model Content
[0005] In view of this, the first purpose of the utility model is to provide a detection device, which can effectively solve the problem of low transmission and reception efficiency of current detection devices. The second purpose of the utility model is to provide a laser radar including the above-mentioned detection device.
[0006] In order to achieve the above object, the utility model provides the following technical solutions:
[0007] A detection device includes a light source component, a polarization splitter element and a receiving component, wherein the light source component is used to emit initial polarized light to be incident on the front side of a first area of the polarization splitter element, the front side of the first area is parallel to the polarization direction of the initial polarized light so that it can be reflected toward a target object; the first area can allow light in the light returned by the target object with a polarization direction different from that of the initial polarized light to be transmitted so as to be received by the receiving component.
[0008] In the above detection device, when in use, compared with the prior art, the relative position relationship between the light source assembly and the polarization splitter element is adjusted so that the front of the first area is parallel to the polarization direction of the initial polarized light directly emitted by the light source assembly, so that it can be reflected toward the target object to meet the polarization splitting requirements of the first area. In the above detection device, by reasonably arranging the relative positions of the light source assembly and the polarization splitter element, the modulation device is omitted, the volume is reduced, the cost is saved, the difficulty of installation and adjustment is reduced, the loss of light energy is further reduced, and it helps to improve the laser radar receiving and transmitting efficiency. In summary, the detection device can effectively solve the problem of low receiving and transmitting efficiency of current detection devices.
[0009] In some technical solutions, the polarization beam splitting element further includes a second area surrounding the first area, and the second area is capable of allowing the light returned by the target object to pass through so as to be received by a receiving component.
[0010] In some technical solutions, the second region has an anti-reflection film.
[0011] In some technical solutions, the front side of the first area is coated with a polarization splitting film.
[0012] In some technical solutions, the polarization splitting element is a plate, and the angle between it and the initial polarized light is 45 degrees.
[0013] In some technical solutions, the light source assembly includes a light source and a collimating assembly, and the collimating assembly is used to collimate the light emitted by the light source to form the initial polarized light.
[0014] In some technical solutions, the polarization beam splitter element is a square area, the first area is located in the central area of the polarization beam splitter element and is also square, and the area of the polarization beam splitter element outside the first area is the second area.
[0015] In some technical solutions, the initial polarized light is linearly polarized light.
[0016] In some technical solutions, a converging component is further provided between the receiving component and the polarization beam splitting element to converge the light transmitted by the polarization beam splitting element and transmit it to the receiving component.
[0017] In some technical solutions, the light source assembly includes a semiconductor laser.
[0018] In order to achieve the second objective, the utility model further provides a laser radar, which includes any of the above detection devices. Since the above detection device has the above technical effects, the laser radar having the detection device should also have corresponding technical effects. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 It is a schematic diagram of the optical path of an existing detection device;
[0021] Figure 2 A schematic diagram of an optical path of a detection device provided in an embodiment of the utility model;
[0022] Figure 3 A schematic diagram of the structure of a polarization beam splitter provided in an embodiment of the utility model;
[0023] Figure 4 A schematic diagram of the optical path of a detection device provided in an embodiment of the utility model.
[0024] The following are marked in the accompanying drawings:
[0025] Light source component 101 , P polarized light 102 , modulation device 103 , S polarized light 104 , polarization beam splitter 105 , target object 106 , scattered light 107 , receiving component 108 , and P polarized light 111 .
[0026] Light source component 1, polarization beam splitter 2, receiving component 3, initial polarized light 4, target 5, scattered light 6;
[0027] The first area 2-1 and the second area 2-2.
[0028] The solid line represents the light emitted by the light source, and the dotted line represents the light reflected by the target object. DETAILED DESCRIPTION
[0029] The embodiment of the utility model discloses a detection device, which effectively solves the problem that the current detection device has low transmission and reception efficiency.
[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0031] See also Figure 2-Figure 4 , Figure 2 A schematic diagram of an optical path of a detection device provided in an embodiment of the utility model; Figure 3 A schematic diagram of the structure of a polarization beam splitter provided in an embodiment of the utility model; Figure 4 A schematic diagram of the optical path of a detection device provided in an embodiment of the utility model.
[0032] In some embodiments, a detection device is provided, specifically a laser radar detection device, which mainly includes a light source component 1 , a polarization beam splitting element 2 and a receiving component 3 .
[0033] The light source component 1 emits initial polarized light 4, and the polarization splitter element 2 can reflect the initial polarized light 4. The reflected light encounters the target object 5, and at least part of the light is reflected back by the target object 5 to form reflected light, that is, scattered light 6. The reflected light can be transmitted through the polarization splitter element 2 and then received by the receiving component 3, which forms a corresponding electrical signal.
[0034] In the above-mentioned detection device, the relative position relationship between the light source component 1 and the polarization splitter element 2 is adjusted so that the initial polarized light 4 emitted by the light source component 1 is S polarized light, which refers to polarized light whose polarization direction is perpendicular to the plane where the incident light and the reflected light are located, so that the polarization splitter element 2 can reflect it out.
[0035] Specifically, the light source assembly 1 can emit the initial polarized light 4 to be incident on the front of the first area 2-1 of the polarization beam splitter 2, and the front of the first area 2-1 is parallel to the polarization direction of the initial polarized light 4 so that it can be reflected toward the target 5 to form the above-mentioned S polarized light. That is, the light source assembly 1 is rotated 90 degrees based on the previous position, so that the light emitted by the light source assembly 1 is converted from P polarized light to the above-mentioned S polarized light to meet the reflection requirements of the polarization beam splitter 2, and no modulation element is needed.
[0036] At least a portion of the light reflected to the target object 5 will be reflected back by the target object 5, i.e., scattered light 6, and enter the first area 2-1. Similarly, the first area 2-1 can allow the light with a different polarization direction from the initial polarized light 4 in the light returned by the target object 5 to be transmitted to be received by the receiving component 3. It should be noted that since the scattered light 6 reflected back by the target object 5 is relatively messy and has an uncertain polarization direction, it can also be considered that it has various polarization directions, and therefore contains light that can be transmitted from the first area 2-1.
[0037] The following is a further specific description: For the convenience of description, the coordinates XYZ are introduced, wherein the Z axis is parallel to the first region 2-1, wherein the X axis and the Y axis are both arranged to intersect the first region 2-1, and wherein the Z axis, the X axis and the Y axis are arranged to be perpendicular to each other. Figure 4 As shown, the modulation device is removed. If the light source assembly 1 still emits P polarized light with a polarization direction along the z direction (a direction parallel to the first region 2-1 as shown in the figure), it is directly incident on the first region 2-1 of the polarization splitter element 2. Since the polarization direction does not meet the requirements of the first region 2-1, the light is directly transmitted by the polarization splitter element 21 and cannot be emitted to the target object 5 to complete the detection.
[0038] As attached Figure 2 As shown, compared with the attached Figure 4 , the angle between the light source component 1 and the polarization beam splitter 2 is rotated 90° along the y-axis, so that the original P polarized light becomes S polarized light for the polarization beam splitter 2, that is, the initial polarized light 4, so that the initial polarized light 4 satisfies the polarization beam splitting requirements of the first area 2-1 of the polarization beam splitter 2 without the need for a modulation element, and the light is reflected onto the target 5. It should be noted that the above position adjustment is a relative rotation, which can be to adjust the position of the light source component 1, or to adjust the position of the polarization beam splitter 2 and the receiving component 3, so that the front of the first area 2-1 is parallel to the polarization direction of the initial polarized light 4 so that it can be reflected toward the target 5.
[0039] In the above detection device, when in use, compared with the prior art, the relative position relationship between the light source assembly 1 and the polarization splitter element 2 is adjusted so that the front of the first area 2-1 is parallel to the polarization direction of the initial polarized light 4 directly emitted by the light source assembly 1, so that it can be reflected toward the target object 5 to meet the polarization splitting requirements of the first area 2-1. In the above detection device, by reasonably arranging the relative positions of the light source assembly 1 and the polarization splitter element 2, the modulation device is omitted, the cost is saved, the volume is reduced, the difficulty of installation and adjustment is reduced, and the loss of light energy is further reduced, which helps to improve the laser radar transceiver efficiency. In summary, the detection device can effectively solve the problem of low transceiver efficiency of current detection devices.
[0040] In some embodiments, since the reflection area of the target object 5 is relatively wide, in order to improve the receiving efficiency of the receiving component 3, the polarization beam splitting element 2 may further include a second area 2-2 surrounding the first area 2-1, and the second area 2-2 may allow the light returned by the target object 5 to be transmitted so as to be received by the receiving component 3, and the second area 2-2 may preferably be able to transmit light of various polarization directions. The second area 2-2 surrounds the first area 2-1, and may be fully surrounded or half-enclosed. When fully surrounded, the inner and outer boundaries of the second area 2-2 may be further arranged to be equal in distance along the circumferential direction.
[0041] In some embodiments, further, in order to improve the transmission efficiency, the second region 2 - 2 may have an anti-reflection film, specifically, may be coated with an anti-reflection film, so as to effectively improve the transmission efficiency.
[0042] In some embodiments, further, the front side of the first region 2 - 1 may be coated with a polarization splitting film so that the front side of the first region 2 - 1 has a better polarization splitting effect.
[0043] The first area 2-1 is generally consistent with the size of the light source emitted by the light source assembly 1, and can be a circular area, a square area, or a triangular area. The outer boundary shape of the second area 2-2 is preferably similar to the shape of the first area 2-1, but different in size. Specifically, if the polarization beam splitter element 2 is a square area, the first area 2-1 is located in the central area of the polarization beam splitter element 2 and is also square, and the area of the polarization beam splitter element 2 outside the first area 2-1 is the second area 2-2.
[0044] In some embodiments, the polarization beam splitter 2 is generally a plate, and forms a certain angle with the incident direction of the initial polarized light 4 to facilitate the reflection of the initial polarized light 4. In order to facilitate the arrangement of various structures, the angle between the polarization beam splitter 2 and the initial polarized light 4 can be 45 degrees, and of course it can also be 50 degrees, 30 degrees, etc.
[0045] When the angle between the polarization beam splitter element 2 and the initial polarized light 4 is 45 degrees, the polarization beam splitter element 2, the light source assembly 1 and the receiving assembly 3 can be distributed in a right triangle, wherein the polarization beam splitter element 2 is located at the right angle point of the right triangle, and the light source assembly 1 and the receiving assembly 3 are respectively located at the two complementary angle points of the right triangle. The receiving assembly 3 is arranged on the back side of the polarization beam splitter element 2.
[0046] In some embodiments, the light source assembly 1 may specifically include a light source and a collimation assembly, and the collimation assembly is used to collimate the light emitted by the light source to form the initial polarized light 4. It may include only the light source and the collimation assembly, or other structures may be provided outside the light source and the collimation assembly, wherein the light source is preferably a semiconductor laser, emitting 905nm laser, which is S polarized light. The optical structure of the collimation assembly is not limited, and it is sufficient to collimate the light emitted by the light source, and the collimation assembly may include a convex lens, a plano-convex lens, a concave lens, a plano-concave lens or a cylindrical mirror. As an optional embodiment, the collimation assembly may include a first collimation element and a second collimation element, the first collimation element is used to collimate the light emitted by the light source in the first axial direction, and the second collimation element is used to collimate the emitted light of the first collimation element in the second axial direction, so that the light emitted by the light source is collimated in the first axial direction and the second axial direction respectively after passing through the collimation assembly. The first collimation element may be a light transmission through the first collimation element, and the transmitted light is collimated in the first axial direction based on the refraction of the light, and the second collimation element may be a light transmission through the second collimation element, and the transmitted light is collimated in the second axial direction based on the refraction of the light. The first collimating element may be a cylindrical mirror, and the second collimating element may be a cylindrical mirror or a spherical mirror.
[0047] In some embodiments, the light source assembly 1 may only include the above light source.
[0048] In some embodiments, the initial polarized light 4 emitted by the light source assembly 1 is linearly polarized light, but it may also be linearly polarized light, circularly polarized light or elliptically polarized light.
[0049] In some embodiments, in order to enable the receiving component 3 to better receive light, it is preferred that a convergence component is also provided between the receiving component 3 and the polarization beam splitter element 2 to converge the light transmitted by the polarization beam splitter element 2 and transmit it to the receiving component. Specifically, the convergence component can include a positive lens and a negative lens, the focal length of the positive lens is 9mm to 10mm, and the focal length of the negative lens is 8mm to -7mm. The positive lens and the negative lens constitute a telephoto optical system, which can realize long focal length and small field of view detection of return light with a short total length.
[0050] In some embodiments, a detection device is provided, which specifically includes a light source component 1, a polarization beam splitter element 2 and a receiving component 3. The laser emitted by the light source component 1 is linearly polarized light with a certain polarization direction. The polarization beam splitter element 2 has two regions, and the first region 2-1 is located in the central part of the polarization beam splitter element 2 and is coated with a polarization beam splitter film. The second region 2-2 is the remaining portion after removing the first region 2-1, and the region is coated with an anti-reflection film. The polarization beam splitter film of the first region 2-1 will reflect the polarized light (S polarized light) whose polarization direction is perpendicular to the plane where the incident light and the reflected light are located, and transmit the polarized light (P polarized light) whose polarization direction is parallel to the plane where the incident light and the reflected light are located. If the laser emitted by the light source component 1 meets the splitting requirements of the first region 2-1, it will be reflected by the polarization beam splitter element 2 to the distant target 5, and the reflected and scattered light of the target 5 will be incident on the polarization beam splitter element 2 again. If the light incident on the first region 2-1 of the polarization beam splitter element 2 is P polarized light, it will be transmitted by the first region 2-1 and enter the receiving component 3. The light incident on the second area 2-2 of the polarization splitter element 2 will be transmitted by area 2 regardless of its polarization direction and enter the receiving component 3. In the prior art, in order to make the polarization direction of the light source meet the splitting requirements of the first area 2-1 of the polarization splitter element 2, a modulation element is added. However, this embodiment is achieved by adjusting the relative position of the light source component 1 and the polarization splitter element 2, eliminating the modulation element. On the basis that the linear polarized light emitted by the light source component 1 is P polarized light, the relative position of the light source component 1 and the polarization splitter element 2 is rotated 90° to make it S polarized light, which is reflected by the first area 2-1 of the polarization splitter element 2, thereby eliminating the use of the modulation device, saving costs, reducing the volume, reducing the difficulty of installation and adjustment, further reducing the loss of light energy, and improving the distance detection capability of the laser radar.
[0051] Based on the detection device provided in the above embodiment, the utility model further provides a laser radar, which includes any one of the detection devices in the above embodiment. Since the laser radar adopts the detection device in the above embodiment, please refer to the above embodiment for the beneficial effects of the laser radar.
[0052] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.
[0053] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A detection device, characterized in that: It includes a light source component, a polarization splitter element and a receiving component. The light source component is used to emit initial polarized light to be incident on the front side of a first area of the polarization splitter element. The front side of the first area is parallel to the polarization direction of the initial polarized light so that it can be reflected toward a target object. The first area can allow light in the light returned by the target object that has a different polarization direction from the initial polarized light to be transmitted so as to be received by the receiving component.
2. The detection device according to claim 1, characterized in that: The polarization beam splitting element further includes a second area surrounding the first area, and the second area is capable of allowing the light returned by the target object to pass therethrough so as to be received by the receiving component.
3. The detection device according to claim 2, characterized in that: The second region has an anti-reflection film.
4. The detection device according to claim 2, characterized in that: The front side of the first area is coated with a polarization splitting film.
5. The detection device according to claim 4, characterized in that: The polarization beam splitting element is a plate, and the angle between the polarization beam splitting element and the initial polarized light is 45 degrees.
6. The detection device according to claim 5, characterized in that: The light source assembly includes a light source and a collimating assembly, and the collimating assembly is used to collimate the light emitted by the light source to form the initial polarized light.
7. The detection device according to claim 6, characterized in that: The polarization beam splitter element is a square area, the first area is located in the central area of the polarization beam splitter element and is also square, and the area of the polarization beam splitter element outside the first area is the second area.
8. The detection device according to claim 7, characterized in that: The initial polarized light is linearly polarized light; and the light source assembly includes a semiconductor laser.
9. The detection device according to claim 8, characterized in that: A converging component is further provided between the receiving component and the polarization beam splitting element to converge the light transmitted by the polarization beam splitting element and transmit the light to the receiving component.
10. A laser radar, characterized in that: Comprising a detection device as described in any one of claims 1-9.