CN114545367A - Laser radar transmitting system - Google Patents

Laser radar transmitting system Download PDF

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Publication number
CN114545367A
CN114545367A CN202210181407.3A CN202210181407A CN114545367A CN 114545367 A CN114545367 A CN 114545367A CN 202210181407 A CN202210181407 A CN 202210181407A CN 114545367 A CN114545367 A CN 114545367A
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lens
sub
transmission system
light source
laser radar
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Inventor
郝成龙
谭凤泽
朱瑞
朱健
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Shenzhen Metalenx Technology Co Ltd
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Shenzhen Metalenx Technology Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/491—Details of non-pulse systems
    • G01S7/4911—Transmitters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Semiconductor Lasers (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

The application provides a laser radar transmitting system, belongs to optics technical field. The laser radar transmitting system comprises a first lens, a second lens and a light source; wherein the first lens comprises a plurality of arrays of sub-lenses; the light source comprises a plurality of arrays of sub-light sources; the first lens and the second lens are coaxial and are sequentially arranged on the light emitting side of the light source; the sub super lens and the sub light source are in a mapping relation. The laser radar transmitting system reduces the number of lenses of the laser radar transmitting system by adopting the first lens and the second lens formed by the sub-lens array, thereby reducing the total length and the working distance of the laser radar transmitting system and promoting the miniaturization and the light weight of the laser radar transmitting system.

Description

Laser radar transmitting system
Technical Field
The application relates to the technical field of optics, in particular to a laser radar transmitting system.
Background
Lidar (Laser detection and Ranging) is a radar system that detects characteristic quantities such as a position, a velocity, and the like of an object by emitting a Laser beam. In general, a lidar includes a transmitting system, a receiving system, an information processing system, and a scanning system. The laser radar transmitting system comprises an optical system and a light source, wherein the optical system and the light source are composed of a plurality of groups of refraction lenses.
In the prior art, a traditional scanning mechanism is replaced by a Micro-vibration mirror (MEMS, Micro-Electro-Mechanical System), so that the size and the weight of the laser radar are reduced, and the miniaturization and the light weight of the laser radar are realized.
However, a method for realizing miniaturization and light weight of the laser radar by reducing the scanning mechanism has been a bottleneck, and therefore, a laser radar having a smaller volume and a lighter weight is demanded.
Disclosure of Invention
For solving the technical problem that laser radar is miniaturized and falls into the bottleneck with the lightweight among the prior art, the embodiment of the application provides a laser radar transmitting system. The laser radar transmitting system comprises a first lens, a second lens and a light source;
wherein the first lens comprises a plurality of arrays of sub-lenses;
the light source comprises a plurality of arrays of sub-light sources;
the first lens and the second lens are coaxial and are sequentially arranged on the light emitting side of the light source;
the sub super lens and the sub light source are in a mapping relation.
Optionally, the sub-lens is a superlens or a microlens array.
Optionally, the sub-lens and the sub-light source are in one-to-one mapping.
Optionally, a ratio of the working distance of the laser radar transmitting system to the equivalent focal length is less than or equal to 0.1.
Optionally, a ratio of a total system length of the lidar transmission system to the equivalent focal length is less than or equal to 0.1.
Optionally, the working distance of the lidar transmission system is less than or equal to 8 mm.
Optionally, the total system length of the lidar transmission system is less than or equal to 10 times the working distance.
Optionally, the lidar transmission system at least satisfies:
D＝2h+fMLAtan(θ)≤P；
wherein θ is a half divergence angle of the sub-light source; f. ofMLAIs the focal length of the sub-lens; d is the aperture of the sub-lens; 2h is the diameter of the sub-light source; and P is the spacing between adjacent sub-light sources.
Optionally, the lidar transmission system at least satisfies:
Figure BDA0003521184640000021
wherein 2 thetanThe divergence angle of the second light ray after being collimated by the sub-lens is shown; f. ofMLAIs the focal length of the sub-lens; h is the radius of the sub-light source.
Optionally, the second lens is a monolithic superlens.
Optionally, the second lens element is a lens group; the lens group comprises at least two lenses.
Optionally the second lens comprises two superlenses; or two refractive lenses.
Optionally, the second lens comprises a piece of superlens and a piece of refractive lens.
The laser radar transmitting system provided by the embodiment of the application at least has the following beneficial effects:
the laser radar transmitting system provided by the embodiment of the application forms mapping through the sub light sources of the array in the light source and the sub lens in the first lens, the sub light sources are accurately modulated, and the total system length and the working distance of the laser radar transmitting system are compressed by the first lens and the second lens which comprise at least one super lens. The laser radar transmitting system also improves the collimation degree of the emergent ray through the first lens and the second lens, so that the divergence angle of the emergent ray passing through the laser radar transmitting system is smaller than 0.3 degrees. According to the embodiment of the application, the sub-lens array and the second lens are adopted, so that the ratio of the total system length of the laser radar transmitting system to the equivalent focal length is smaller than 0.5; the ratio of the working distance to the equivalent focal length is less than 0.1; meanwhile, the total length, the small working distance and the high collimation of a small system are met; thereby promoting miniaturization and weight reduction of the laser radar transmission system. The laser radar transmitting system provided by the embodiment of the application has the advantages of light weight, small size, simple structure and low cost.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings required to be used in the embodiments or the background art of the present application will be described below.
Fig. 1 is a schematic diagram illustrating an alternative structure of a lidar transmission system provided in an embodiment of the present application;
FIG. 2 is a schematic diagram illustrating an alternative configuration of a lidar transmission system provided by an embodiment of the present application;
FIG. 3 is a schematic diagram illustrating an alternative configuration of a lidar transmission system provided by an embodiment of the present application;
FIG. 4 is a schematic diagram illustrating an alternative configuration of a lidar transmission system provided by an embodiment of the present application;
FIG. 5 is a schematic diagram illustrating a mapping of sub-lenses and sub-light sources provided by embodiments of the present application;
FIG. 6 is a schematic diagram of an alternative structure of a nanostructure provided by an embodiment of the present application;
FIG. 7 shows a schematic diagram of yet another alternative structure of a nanostructure provided by an embodiment of the present application;
FIG. 8 is a schematic diagram illustrating an alternative structure of a superstructure unit provided by an embodiment of the present application;
FIG. 9 shows a schematic diagram of yet another alternative structure of a superstructure unit provided by embodiments of the present application;
FIG. 10 shows a schematic diagram of yet another alternative structure of a superstructure unit provided by embodiments of the present application;
fig. 11 shows a graph of transmittance versus phase modulation for an alternative nanostructure provided by an embodiment of the present application.
The reference numerals in the drawings denote:
100-a first lens; 200-a second lens; 300-a third lens; 400-a fourth lens;
300-light source.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Also, in the drawings, the thickness, ratio and size of the components are exaggerated for clarity of illustration.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present. The terms "mounted," "one end," "the other end," and the like are used herein for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, "a," "an," "the," and "at least one" do not denote a limitation of quantity, but rather are intended to include both the singular and the plural, unless the context clearly dictates otherwise. For example, "a component" means the same as "at least one component" unless the context clearly dictates otherwise. "at least one of" should not be construed as limited to the quantity "one". The term "and/or" includes any and all combinations of one or more of the associated listed items.
The meaning of "comprising" or "comprises" indicates a property, a quantity, a step, an operation, a component, a part, or a combination thereof, but does not exclude other properties, quantities, steps, operations, components, parts, or combinations thereof.
Embodiments are described herein with reference to cross-sectional views that are idealized embodiments. Thus, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, regions shown or described as flat may typically have rough and/or nonlinear features. Also, the acute angles shown may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.
With the landing use of laser radar in consumer electronics and automotive electronics industries, miniaturization and light weight become an urgent problem to be solved. Especially, the size and the weight of the existing laser radar are still difficult to meet the application requirements in the fields of unmanned aerial vehicles and the like. The present application further realizes the miniaturization and lightweight of the lidar by compressing the volume and weight of the lidar transmission system, and more specifically, by compressing the volume and weight of the optical system in the lidar transmission system.
In order to reduce the volume of the laser radar, it is necessary to suppress The Total Length (TTL) of the laser radar transmission system as much as possible. The overall system length of the lidar receiving system refers to the distance from the center of the first optical element of the lens in the receiving system to the center of the focal plane along the incident direction. Therefore, the smaller the lens thickness, the smaller the number of lenses, and the shorter the focal length of the lens, the smaller the total system length.
The Working Distance (WD) of a lidar transmission system is the Distance from the light emitting surface of the light source to the surface of the first lens in the transmission system in the emission direction. In addition to reducing the number of lenses, reducing the thickness of the lenses, and shortening the spacing between the lenses, the volume of the lidar transmission system may be reduced by reducing the working distance. It should be noted that the smaller the working distance, the more advantageous the integration of the lidar transmission system.
The collimation degree of the emergent light is one of important indexes for evaluating the optical performance of the laser radar transmitting system. The volume of the laser radar transmitting system is reduced by reducing the total length and the working distance of the system, and the premise of ensuring the optical performance is needed. The existing laser radar transmitting system is generally composed of at least four groups of refraction lenses, and the structure is difficult to simultaneously meet the requirements of small total length of the system, small working distance and high collimation degree.
Therefore, a laser radar transmitting system satisfying a small overall length of the system, a small working distance and a high degree of collimation at the same time is needed.
Fig. 1 to 4 illustrate a lidar transmitting system provided in an embodiment of the present application. As shown in fig. 1 to 4, the lidar transmission system includes a first lens 100, a second lens 200, and a light source 300. Wherein the first lens 100 includes a plurality of arrays of sub-lenses 101. The light source 300 comprises a plurality of arrays of sub-light sources 301. The first lens 100 and the second lens 200 are coaxial and are sequentially disposed on the light emitting side of the light source 300. The sub superlens 101 and the sub light source 301 are in a mapping relationship. The light emitted from the light source 300 sequentially passes through the first lens 100 and the second lens 200, and the divergence angle is less than 0.3 °.
According to the embodiment of the present application, the sub-Lens 101 may be a super Lens or a Micro Lens Array (MLA). The micro lens array is an array composed of lenses with micron-sized clear aperture and relief depth. The lens is the same as the traditional lens, the minimum functional unit can be a spherical mirror, an aspherical mirror, a cylindrical lens, a prism and the like, the functions of focusing, imaging, light beam conversion and the like can be realized at a micro-optical angle, and because the unit size is small and the integration level is high, the lens can form a plurality of novel optical systems to complete the functions which cannot be completed by the traditional optical element. Optionally, the sub-light source 301 is a Laser light source, such as a Vertical External Surface Emission Laser (VECSEL).
According to the embodiment of the present application, the mapping relationship between the sub-light sources 301 and the sub-lenses 101 may be a one-to-many mapping, that is, one sub-lens 101 corresponds to a plurality of sub-light sources 301. It should be understood that the mapping relationship may also be a many-to-one mapping, i.e. one sub-light source 301 corresponds to a plurality of sub-lenses 101. Preferably, as shown in fig. 5, the mapping relationship is a one-to-one mapping, i.e. one sub-lens 101 is responsible for modulating the light emitted by one sub-light source 301. It should be noted that many-to-many mapping is also possible, i.e. the light emitted by the sub-light sources 301 is modulated by the sub-lenses 101. The embodiment of the present application is illustrated only by a structure of one-to-one mapping.
Specifically, the ratio of the Working Distance (WD) to the Equivalent Focal Length (EFL) of the laser radar transmitting system is less than or equal to 0.1, namely WD/FL is less than or equal to 0.1. The ratio of total system Length (TTL) to Equivalent Focal Length (EFL) of the laser radar transmitting system is less than or equal to 0.5, namely TTL/EFL is less than or equal to 0.5. The first lens 100 and the second lens 200 are disposed on the light emitting side of the light source 300 in order of the optical axis. Preferably, the laser radar transmission system has a working distance of less than or equal to 8 mm. More preferably, the overall system length of the lidar transmission system is less than or equal to 10 working distances.
As shown in fig. 5, the first light emitted from each sub-light source 301 is modulated by the corresponding sub-superlens 101 to form a second light. As shown in fig. 1 to 4, the second light is modulated or refracted by the second lens 200 to form a third light. The divergence angle of the first light ray, i.e., the divergence angle of the sub light source 301, is 2 θ; the divergence angle of the second light ray, i.e., the divergence angle of the sub-lens 101, is 2 θn(ii) a Divergence angle of the third ray is 2 thetaout。
In an alternative embodiment, to ensure that the light emitted from the light source 300 does not overlap on the first lens 100, the lidar emitting system provided in the embodiment of the present application satisfies the following formula (1):
D＝2h+fMLAtan(θ)≤P (1)；
in formula (1), θ is the half divergence angle of the sub-light source 301; f. ofMLAIs the focal length of the sub-lens 101; d is the aperture of the sub-lens 101(ii) a 2h is the diameter of the sub-light source 301; p is the pitch between adjacent sub-light sources 301. When the section of the sub-light source 301 perpendicular to the optical axis is not circular, the diameter of the sub-light source 301 refers to the diameter of its circumscribed circle.
Further, according to the embodiment of the present application, optionally, in order for the first lens 100 to collimate the light emitted by the light source 300, the laser radar transmission system satisfies the following formula (2):
Figure BDA0003521184640000071
in the formula (2), 2 θnThe divergence angle of the second light collimated by the sub-lens 101; f. ofMLAIs the focal length of the sub-lens 101; h is the radius of the sub-light sources 301.
According to the embodiment of the present application, it is more advantageous that the second lens 200 is located on the focal plane of the first lens 100 so that the second light modulated by the first lens 101 is incident on the second lens 200 as much as possible. The second lens 200 is preferably a single super lens, but when the focal power of the single super lens cannot meet the requirement, the number of lenses can be increased to form a lens group, so that the optical performance of the second lens 200 meets the requirement of the laser radar transmitting system.
In some embodiments of the present application, as shown in fig. 1, the second lens 200 is a monolithic superlens. Divergence angle of 2 thetanThe second light ray of (2) forms a divergence angle of 2 theta after being modulated by the periodically arranged nano-structures on the surface of the second lens 200outThe third light ray. The third light is the outgoing light of the laser radar transmitting system provided by the embodiment of the application.
In still other embodiments of the present application, as shown in fig. 2, the second lens 200 is a single-piece refractive lens. Divergence angle of 2 thetanThe second light ray is refracted by the second lens 200 to form a divergence angle of 2 thetaoutThe third light ray. The third light is the outgoing light of the laser radar transmitting system provided by the embodiment of the application.
In still other embodiments of the present application, as shown in fig. 3 and 4, the second lens element 200 is a lens group including at least two coaxially disposed lens elements. Illustratively, as shown in fig. 3, the second lens 200 includes two pieces of superlenses; alternatively, the second lens 200 includes a piece of superlens and a piece of refractive lens; still alternatively, the second lens 200 includes two refractive lenses.
It should be noted that the refractive lens in any of the above embodiments may be a single refractive lens, but in practical applications, a refractive lens may be formed by combining a plurality of lenses with different curvatures.
Next, a super lens used in the embodiment of the present application will be explained. The super lens is a specific application of a super surface, the surface of the super lens is provided with periodically arranged nano structures, and the characteristic size of each nano structure is a sub-wavelength size. The characteristic dimensions include the dimensions of the nanostructure, such as diameter, perimeter, and height. Sub-wavelength dimensions refer to dimensions that are less than or equal to the incident wavelength, or in some cases may be slightly larger than the incident wavelength. The superlens modulates the phase, amplitude and polarization of incident light by the periodically arranged sub-wavelength size nano-structures.
Fig. 6 and 7 are perspective views illustrating a nanostructure of a superlens employed in a lidar transmission system provided by an embodiment of the present application. Optionally, the superlens may be filled with air or other material that is transparent or translucent in the operating band between the nanostructures. According to embodiments of the present application, the absolute value of the difference between the refractive index of the filled material and the refractive index of the nanostructure should be greater than or equal to 0.5. As shown in fig. 6, the nanostructures may be polarization dependent structures that impart a geometric phase to incident light. As shown in fig. 7, the nanostructures may be polarization independent structures that impart a propagation phase to incident light.
According to an embodiment of the present application, a superlens includes a substrate and a microstructure layer disposed on the substrate, as shown in fig. 8 to 10, wherein the microstructure layer includes superstructure units arranged in an array.
As shown in fig. 8, according to an embodiment of the present application, the superstructure units may be arranged in a fan shape. As shown in fig. 9, according to an embodiment of the present application, the superstructure units may be arranged in an array of regular hexagons. Further, as shown in fig. 10, according to an embodiment of the present application, the superstructure units may be arranged in a square array. Those skilled in the art will recognize that the superstructure units included in the microstructure layer may also include other forms of array arrangements, and all such variations are contemplated within the scope of the present application.
According to embodiments of the present application, the superstructure unit may have a nanostructure. As shown in fig. 8 to 10, according to an embodiment of the present application, a nanostructure is disposed at a central position and/or a vertex position of each microstructure unit, respectively. According to an embodiment of the present application, the nanostructure is an all-dielectric building block. Optionally, the working wavelength band of the superlens in the embodiment of the present application is a common wavelength band of the laser radar, including a near infrared wavelength band, such as 850nm, 905nm, 940nm, and 1550 nm. According to an embodiment of the present application, the nanostructure has a high transmittance in the near infrared light band. According to embodiments of the present application, the nanostructures may be formed of at least one of the following materials: titanium oxide, silicon nitride, fused silica, aluminum oxide, gallium nitride, gallium phosphide, amorphous silicon, crystalline silicon, hydrogenated amorphous silicon, and the like.
The transmittance and phase modulation relationship of an alternative nanostructure provided by the embodiments of the present application is shown in fig. 11. FIG. 11 shows a graph of transmittance versus phase modulation for 1200nm high silicon nanostructures in a regular quadrilateral arrangement with a period of 600 nm.
Example 1
Illustratively, the embodiment of the present application provides a laser radar transmission system, which includes a first lens 100, a second lens 200 and a light source 300, as shown in fig. 1. The first lens 100 includes a plurality of sub-lenses 101, and the sub-lenses 101 are superlenses. The lens 200 includes two superlenses. The light source 300 includes a plurality of sub light sources 301 arranged in an array. The key parameters of the laser radar transmitting system are shown in table 1, and the working wavelength band is 1550 nm.
TABLE 1
Diameter of sub-light source 1μm
Spacing of adjacent sub-light sources 20μm
Semi-divergence angle of sub-light source (theta) 10°
Sub-lens focal length (f)MLA) 54μm
Divergence angle (theta) after passing through first lensn) 0.53°
Subsequent Total System Length (TTL) 8.5mm
Follow-up system Working Distance (WD) 0.5mm
Divergence angle after collimation (2 theta)out) 0.2°
As shown in Table 1, after a 200 μm light source 300 is collimated by the first lens 100 and the second lens 200 in the lidar transmission system provided in this embodiment, the divergence angle 2 θ of the outgoing light isoutLess than 0.2 degrees, and meets the requirements of a scanning laser radar transmitting system. The total length of the subsequent system in Table 1 is from the incident surface of the first lens 100 to the second lensThe distance of the exit face of the mirror 200. The subsequent system working distance in table 1 refers to the distance from the incident surface of the first lens 100 to the incident surface of the second lens 200.
Example 2
Illustratively, the present embodiment provides a lidar transmission system, which includes a first lens 100, a second lens 200, and a light source 300, as shown in fig. 4. The first lens 100 includes a plurality of sub-lenses 101, and the sub-lenses 101 are superlenses. The lens 200 includes a piece of superlens and a piece of refractive lens. The light source 300 includes a plurality of sub light sources 301 arranged in an array. The key parameters of the laser radar transmitting system are shown in table 2, and the working wavelength band is 1550 nm.
TABLE 2
Figure BDA0003521184640000101
Figure BDA0003521184640000111
As shown in Table 2, after the 200 μm light source 300 is collimated by the first lens 100 and the second lens 200 in the lidar transmission system provided in this embodiment, the divergence angle 2 θ of the outgoing light isoutLess than 0.15 degrees, and meets the requirements of a scanning laser radar transmitting system.
It should be noted that, since the optical path is reversible, the optical system including at least one superlens in the laser radar transmission system provided in the embodiment of the present application may be used in a laser radar reception system.
The superlens adopted by the laser radar transmitting system provided by the embodiment of the application can be processed by a semiconductor process to realize mass production. The semiconductor process can reduce the cost of the super lens and improve the consistency of the mass production of the super lens.
In summary, the lidar transmission system provided in the embodiment of the present application forms a mapping between the sub-light sources of the array in the light source and the sub-lens in the first lens, and the total system length and the working distance of the lidar transmission system are reduced by the first lens and the second lens including at least one super-lens. The laser radar transmitting system also improves the collimation degree of emergent rays through the first lens and the second lens, so that the divergence angle of the emergent rays passing through the laser radar transmitting system is smaller than 0.3 degrees. According to the embodiment of the application, the sub-lens array and the second lens are adopted, so that the ratio of the total system length of the laser radar transmitting system to the equivalent focal length is smaller than 0.5; the ratio of the working distance to the equivalent focal length is less than 0.1; meanwhile, the total length, the small working distance and the high collimation of a small system are met; thereby promoting miniaturization and weight reduction of the laser radar transmission system. The laser radar transmitting system provided by the embodiment of the application has the advantages of light weight, small size, simple structure and low cost.
The above description is only a specific implementation of the embodiments of the present application, but the scope of the embodiments of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the embodiments disclosed in the present application, and all the changes or substitutions should be covered by the scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims (13)

1. A lidar transmission system characterized by comprising a first lens (100), a second lens (200), and a light source (300);
wherein the first lens (100) comprises a plurality of arrays of sub-lenses (101);
the light source (300) comprises a plurality of arrays of sub-light sources (301);
the first lens (100) and the second lens (200) are coaxial and are arranged on the light emitting side of the light source (300) in sequence;
the sub super lens (101) and the sub light source (301) are in a mapping relation.
2. Lidar transmission system according to claim 1, wherein said sub-lens (101) is a superlens or a microlens array.
3. The lidar transmission system of claim 1, wherein the sub-lens (101) and the sub-light source (301) are in a one-to-one mapping.
4. The lidar transmission system of any of claims 1-3, wherein a ratio of a working distance of the lidar transmission system to an equivalent focal length is less than or equal to 0.1.
5. The lidar transmission system of any of claims 1-3, wherein a ratio of a total system length to an equivalent focal length of the lidar transmission system is less than or equal to 0.1.
6. The lidar transmission system of any of claims 1-3, wherein the lidar transmission system has a working distance of less than or equal to 8 mm.
7. The lidar transmission system of any of claims 1-3, wherein the overall system length of the lidar transmission system is less than or equal to 10 working distances.
8. The lidar transmission system of any of claims 1-3, wherein the lidar transmission system is configured to at least:
D＝2h+fMLAtan(θ)≤P；
wherein θ is a half divergence angle of the sub light source (301); f. ofMLAIs the focal length of the sub-lens (101); d is the aperture of the sub-lens (101); 2h is the diameter of the sub-light source (301); p is the spacing between adjacent sub-light sources (301).
9. Lidar transmission system according to any of claims 1 to 3, wherein said lidar transmission system is adapted to at least:
Figure FDA0003521184630000021
wherein 2 thetanIs the divergence angle of the second light rays collimated by the sub-lens (101); f. ofMLAIs the focal length of the sub-lens (101); h is the radius of the sub-light source (301).
10. The lidar transmission system of claim 1, wherein said second lens (200) is a single-piece superlens.
11. Lidar transmission system according to claim 1, wherein the second lens (200) is a mirror group; the lens group comprises at least two lenses.
12. Lidar transmission system of claim 1, wherein the second lens (200) comprises two superlenses; or two refractive lenses.
13. Lidar transmission system of claim 1, wherein the second lens (200) comprises a piece of superlens and a piece of refractive lens.
CN202210181407.3A 2022-02-25 2022-02-25 Laser radar transmitting system Pending CN114545367A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115754984A (en) * 2022-11-22 2023-03-07 北醒（北京）光子科技有限公司 Laser transmitter and laser radar
US11927769B2 (en) 2022-03-31 2024-03-12 Metalenz, Inc. Polarization sorting metasurface microlens array device
US11978752B2 (en) 2019-07-26 2024-05-07 Metalenz, Inc. Aperture-metasurface and hybrid refractive-metasurface imaging systems
US11988844B2 (en) 2017-08-31 2024-05-21 Metalenz, Inc. Transmissive metasurface lens integration

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11988844B2 (en) 2017-08-31 2024-05-21 Metalenz, Inc. Transmissive metasurface lens integration
US11978752B2 (en) 2019-07-26 2024-05-07 Metalenz, Inc. Aperture-metasurface and hybrid refractive-metasurface imaging systems
US11927769B2 (en) 2022-03-31 2024-03-12 Metalenz, Inc. Polarization sorting metasurface microlens array device
CN115754984A (en) * 2022-11-22 2023-03-07 北醒（北京）光子科技有限公司 Laser transmitter and laser radar

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