Beam shaping assembly and optical device

Abstract

The application relates to a light beam shaping assembly and an optical device, the light beam shaping assembly comprising a first layer of lenses and a second layer of lenses, the first layer of lenses comprising a plurality of first microlenses, each first microlens being arranged in a first direction and a second direction, the second layer of lenses comprising a plurality of second microlenses, each second microlens being arranged in the first direction, the first layer of lenses and the second layer of lenses being arranged in a third direction; wherein each first microlens has a first front surface and a first back surface in the third direction, and each second microlens has a second front surface and a second back surface in the third direction, the first layer of lenses being configured to collimate and deflect light emitted by a light emitting device so that the light emitted from the first back surface can irradiate the second front surface, and the second layer of lenses being configured to deflect and collimate the light irradiating the second front surface so as to form a line light spot in a far field. The first microlenses and the second microlenses have small volumes, and the light beam shaping assembly has a small volume, and can be used in a small space.

Description

Technical Field

[0001] This application relates to the field of optical instrument technology, and in particular to a beam shaping component and optical device. Background Technology

[0002] A lidar transmitter includes a laser emitter and a beam shaping element for shaping the beam. Through the cooperation of the laser emitter and the beam shaping element, the beam shaping element integrates the light emitted by the laser emitter into a beam with specific properties, which, in conjunction with other components of the lidar, enables the detection of target space. Currently, a lens group is typically used to shape the light emitted by the laser emitter. This lens group includes multiple lenses. Because the lenses are large in size and weight, the beam shaping element is also large in size and weight, affecting the user experience and making it unsuitable for applications with limited space. Summary of the Invention

[0003] This application provides a beam shaping assembly, comprising a first lens layer and a second lens layer. The first lens layer includes a plurality of first microlenses, each of which is arrayed along a first direction and a second direction. The second lens layer includes a plurality of second microlenses, each of which is arrayed along the first direction. The first and second lens layers are distributed along a third direction. The first microlenses along the third direction have a first front surface and a first rear surface, and the second microlenses along the third direction have a second front surface and a second rear surface. The first lens layer is used to collimate and deflect light emitted from a light-emitting device so that light rays emitted from the first rear surface can illuminate the second front surface. The second lens layer is used to deflect and collimate light rays illuminating the second front surface to form a line spot in the far field.

[0004] Therefore, this beam shaping component is used to convert the light emitted by the light-emitting device into a linear light spot in the far field, enabling the optical device to perform corresponding functions when used in optical equipment. Simultaneously, both the first and second microlenses are microlenses. In optical systems, microlenses are used to converge and diverge light, and are so small that they cannot be seen by the human eye; they can only be observed using equipment such as microscopes, scanning electron microscopes, and atomic force microscopes. In the beam shaping element of this application embodiment, because the first and second microlenses are small in size, the beam shaping element is also small in size and weight, thereby reducing the size and weight of the optical device. This beam shaping element and optical device can be used in applications with limited space.

[0005] In one specific embodiment, the optical axis of the first microlens is deviated from its geometric center, and the optical axis of the second microlens is deviated from its geometric center, thereby causing the light emitted through the first microlens to be deflected and projected onto the second microlens. The light emitted from the second microlens is deflected, forming a line spot in the far field.

[0006] In one specific embodiment, the first front surface is a freeform surface, the first rear surface is a plane, and both the second front surface and the second rear surface are freeform surfaces. In this embodiment, the freeform surfaces of the first and second microlenses can form a preset line spot in the far field, ensuring that the linewidth and divergence angle of the line spot meet the user's specific needs.

[0007] In one specific embodiment, the first front surface, the second front surface, and the second rear surface are any one of a sphere, a parabola, or a torus.

[0008] In one specific embodiment, the first microlens is an off-axis aspherical lens, and the second microlens is a far-field lens.

[0009] In one specific embodiment, the first layer lens includes m rows and n columns of first microlenses, and the second layer lens includes 1 row and n columns of second microlenses. In the first layer lens, the j-th first microlens in the i-th column is ij, and the i-th second microlens in the second layer lens is used to shape the light emitted from the i-th column of first microlenses. The optical axes of each second microlens have different coordinates along the first direction, and the optical axes of each second microlens have the same coordinates along the second direction. This allows the small line spots formed in the far field by the structural unit composed of a column of first microlenses and a second microlens to be superimposed in the far field to form a preset line spot, avoiding the small line spots from being misaligned and causing a decrease in the quality of the formed line spot, which would affect the accuracy of the optical device.

[0010] In one specific embodiment, the first lens layer and the second lens layer satisfy the following relationship:

[0011]

[0012]

[0013] i Δy =0;

[0014] Where i is the coordinate of the geometric center of the i-th second microlens along the first direction, i is the coordinate of the geometric center of the i-th second microlens along the second direction, ij is the coordinate of the geometric center of the j-th first microlens in the i-th column along the first direction, and ij is the coordinate of the geometric center of the j-th first microlens in the i-th column along the second direction; ijΔ is the offset of the optical axis of the j-th first microlens in the i-th column relative to its geometric center in the first direction, ijΔ is the offset of the optical axis of the j-th first microlens in the i-th column relative to its geometric center in the second direction, and iΔ is the offset of the optical axis of the i-th second microlens relative to the optical axis of the i-th column first microlens in the second direction; the focal length of each first microlens is the same and is h1, and along the third direction, the distance between the i-th second microlens in the second layer of lenses and the first rear surface is h2.

[0015] In this embodiment, when the structural unit composed of a first microlens and a second microlens satisfies the constraints described above, each structural unit can form a small line spot in the far field, and the small line spots formed by multiple structural units are superimposed in the far field to form a line spot, thereby meeting the user's needs.

[0016] In one specific embodiment, the distance h3 between the geometric centers of adjacent first microlenses along the first direction satisfies: 1 ≤ h3 ≤ 5 mm, and / or the distance h4 between the geometric centers of adjacent first microlenses along the second direction satisfies: 0.02 mm ≤ h4 ≤ 0.1 mm. The distance h3 between the geometric centers of adjacent first microlenses along the first direction is related to the divergence angle of the far-field line spot. The larger h3 is, the smaller the divergence angle of the far-field line spot. However, if h3 is too large, it will lead to an excessively large volume of the beam shaping component. Therefore, the value of h3 can be selected by comprehensively considering both the divergence angle of the desired line spot and the volume of the beam shaping component. When the distance h4 between the geometric centers of adjacent first microlenses along the second direction is small, the overall volume of the beam shaping component can be reduced, thereby reducing the volume of the optical device.

[0017] In one specific embodiment, the aperture of each of the second microlenses is d, and the divergence angle of the far-field line spot formed by the beam shaping component is θ, satisfying:

[0018]

[0019] Where λ is the wavelength of light.

[0020] In this embodiment, when the aperture of the second microlens satisfies the above relationship, the divergence angle of the linear light spot formed on site can be smaller, so as to meet the user's needs.

[0021] In one specific embodiment, the aperture of the first microlens is less than or equal to 32 μm. The aperture of the first microlens is not too large, so that the volume of the beam shaping component is not too large.

[0022] A second aspect of this application provides an optical device, the optical device comprising:

[0023] case;

[0024] A light-emitting device, wherein the light-emitting device is disposed within the housing;

[0025] A beam shaping assembly, the beam shaping assembly being mounted on the housing;

[0026] The beam shaping component is the beam shaping component described above.

[0027] In this embodiment, when the beam shaping component of the optical device is implemented through the first microlens and the second microlens, the size and weight of the optical device are both small, making it suitable for use in situations with limited space. Furthermore, the optical device can convert the light emitted by the light-emitting device into a far-field line spot to meet the user's needs.

[0028] In one specific embodiment, the light-emitting device includes multiple point light sources, which are arrayed along a first direction and a second direction, and each point light source corresponds one-to-one with the first microlens. In this embodiment, the beam shaping component can convert the light emitted by the arrayed point light sources into a far-field line spot.

[0029] In one specific embodiment, the optical axis of the second microlens and the coordinates of the corresponding column of point light sources along the first direction are the same, which can prevent the multiple small line spots formed by each structural unit from deviating from each other along the first direction, so that the small line spots can be superimposed in the far field along the first direction to form a line light spot and improve the quality of the line light spot.

[0030] In one specific embodiment, along the first direction, the distance L1 between adjacent point light sources satisfies: 1 ≤ L1 ≤ 5 mm, and / or, along the second direction, the distance L2 between adjacent point light sources satisfies: 0.02 mm ≤ L2 ≤ 0.1 mm. The distance L1 between adjacent point light sources along the first direction is related to the divergence angle of the far-field line spot. The larger L1 is, the smaller the divergence angle of the far-field line spot. However, if L1 is too large, it will lead to an excessively large volume of the beam shaping component. Therefore, the value of L1 can be selected by comprehensively considering both the divergence angle of the desired line spot and the volume of the beam shaping component. When the distance L2 between adjacent point light sources along the second direction is small, the overall volume of the beam shaping component can be reduced, thereby reducing the volume of the optical device.

[0031] In one specific embodiment, the optical device is a lidar transmitter.

[0032] In one specific embodiment, the optical device is a laser projector.

[0033] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0034] Figure 1 A schematic diagram of the light-emitting device and beam shaping assembly of the optical device provided in this application in a specific embodiment;

[0035] Figure 2 for Figure 1 A diagram from another perspective;

[0036] Figure 3 for Figure 1 A partial structural diagram of the mid-beam shaping component;

[0037] Figure 4 for Figure 3 A schematic diagram of the structure of the first and second microlenses in a specific embodiment;

[0038] Figure 5 for Figure 3 A schematic diagram of the structure of the first and second microlenses in another specific embodiment;

[0039] Figure 6 for Figure 3 A schematic diagram of the structure of the first and second microlenses in yet another specific embodiment;

[0040] Figure 7 for Figure 3 Optical path diagram of the first and second microlenses in a specific embodiment;

[0041] Figure 8 for Figure 2 A partial schematic diagram;

[0042] Figure 9 for Figure 8 A diagram from another perspective;

[0043] Figure 10 for Figure 2 A schematic diagram of a midpoint light source in one specific embodiment.

[0044] Figure label:

[0045] 11 - First layer lens;

[0046] 111 - First microlens;

[0047] 111a - First front surface;

[0048] 111b - First rear surface;

[0049] 12 - Second lens layer;

[0050] 121 - Second microlens;

[0051] 121a - Second front surface;

[0052] 121b - Second rear surface;

[0053] 2-Light-emitting devices;

[0054] 21-Point light source;

[0055] 4-line light spot.

[0056] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0057] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0058] In one specific embodiment, the present application will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0059] This application provides an optical device and a beam shaping component, such as... Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the optical device provided in the embodiments of this application. Figure 2 for Figure 1 Another structural schematic diagram. The optical device includes a housing, a light-emitting device 2, and a beam shaping assembly. Both the light-emitting device 2 and the beam shaping assembly are mounted in the housing, which protects them.

[0060] like Figure 3 As shown, Figure 3 for Figure 1 A schematic diagram of the beam shaping assembly. This beam shaping assembly includes a first lens 11 and a second lens 12. The light-emitting device 2, the first lens 11, and the second lens 12 are distributed along the third direction Z. The light emitted by the light-emitting device 2 is shaped by the first lens 11 and the second lens 12. Wherein, as... Figure 2As shown, the first layer lens 11 includes a plurality of first microlenses 111, each of which is arranged in an array along the first direction X and the second direction Y. The second layer lens 12 includes a plurality of second microlenses 121, each of which is arranged along the first direction X, that is, each second microlens 121 corresponds to a row of first microlenses 111 arranged along the second direction Y.

[0061] In this embodiment, both the first microlens 111 and the second microlens 121 are microlenses. In optical systems, microlenses are used to converge and diverge light. They are small in size and cannot be seen by the human eye; they can only be observed using instruments such as microscopes, scanning electron microscopes, and atomic force microscopes. Because the first microlens 111 and the second microlens 121 are small in size, the beam shaping element is also small in size and weight, which in turn makes the optical device smaller in size and weight. This allows the beam shaping element and the optical device to be used in space-constrained applications.

[0062] It should be noted that in the embodiments of this application, the first direction X can be the linewidth direction of the line spot 4, the second direction Z can be the divergence angle direction of the line spot 4, and the third direction Z is the direction perpendicular to the plane containing the first direction X and the second direction Y.

[0063] Specifically, such as Figure 4-6 As shown, Figure 4-6 for Figure 3 A schematic diagram of the structure of the first and second microlenses. The first microlens 111 has a first front surface 111a and a first rear surface 111b along the third direction Z. The second microlens 121 has a second front surface 121a and a second rear surface 121b along the third direction Z, with the first rear surface 111b facing the second front surface 121a along the third direction Z. When this optical device and beam shaping assembly are working, as... Figure 1 and Figure 2 As shown, and in combination Figure 7 , Figure 7 This is a schematic diagram of the optical path of the first microlens 111 and the second microlens 121. The light emitted by the light-emitting device 2 can illuminate the first front surface 111a of a row of first microlenses 111. The first microlenses 111 can collimate and deflect the light illuminating them, causing the light exiting through the first rear surface 111b of the first microlens 111 to be deflected and illuminate the second front surface 121a of a corresponding second microlens 121. The second microlenses 121 deflect and collimate the light illuminating them, causing the light exiting through the second rear surface 121b of each second microlens 121 to form a line in the far field. Therefore, Figure 7 A small structural unit of the beam shaping assembly shown can form a small line spot in the far field. When the beam shaping assembly includes multiple Figure 7When the structural units shown are used, the small line spots formed by each structural unit in the far field can be superimposed in the far field to form a preset line spot 4.

[0064] Therefore, this beam shaping component is used to convert the light emitted by the light-emitting device 2 into a line spot 4 in the far field, enabling the optical device to perform corresponding functions when used in an optical device. For example, when the optical device is a lidar transmitter, it works in conjunction with a scanning device to achieve distance detection within a target area.

[0065] In this process, since the first microlens 111 is used to collimate and deflect light, its optical axis is deviated from its geometric center, thus causing the light emitted from the first microlens 111 to be deflected. Similarly, since the second microlens 121 is used to deflect and collimate light, its optical axis is deviated from its geometric center, thus causing the light emitted from the second microlens 121 to be deflected.

[0066] In one specific embodiment, such as Figure 4-6 As shown, the first front surface 111a of the first microlens 111 is a freeform surface, the first rear surface 111b is a plane, and the second front surface 121a and the second rear surface 121b are both freeform surfaces. Figure 1 and Figure 2 When the optical device shown is working, the light emitted by the light-emitting device 2 is projected onto the second microlens 121 under the action of the first microlens 111. A row of first microlenses 111 distributed along the second direction Y shares a single second microlens 121. Under the action of the second microlens 121, the light rays projected from the first microlens 111 onto the second microlens 121 have a coordinate of 0 along the first direction X in the far-field plane and diffuse along the second direction Y, forming a line spot 4. The first front surface 111a is used to control the divergence angle of the target far-field line spot 4 formed by the light emitted by the light-emitting device 2 along the second direction Y, and the second rear surface 121b is used to adjust the linewidth of the target far-field line spot 4 along the first direction X.

[0067] Therefore, the freeform surfaces of the first microlens 111 and the second microlens 121 in this embodiment can form a preset line spot 4 in the far field, and make the line width and divergence angle of the line spot 4 meet the specific needs of the user.

[0068] The first front surface 111a, the second front surface 121a, and the second rear surface 121b are any of a sphere, a parabola, or a torus. Of course, the freeform surfaces of the first front surface 111a, the second front surface 121a, and the second rear surface 121b in the embodiments of this application can also be other shapes.

[0069] In one specific embodiment, the first microlens 111 can be an off-axis aspherical lens, and / or the second microlens 121 can also be an off-axis aspherical lens. The aspherical lens has a continuously changing curvature from the center to the periphery, is not spherical, and has a planar cross-section, enabling it to focus light incident on the lens and improve aberrations. Furthermore, the optical axis of the off-axis aspherical lens deviates from its geometric center.

[0070] In the above embodiments, as Figure 8 and Figure 9 As shown, Figure 8 This is a partial schematic diagram of the beam shaping component in the XY plane in one specific embodiment. Figure 9 This is a partial schematic diagram of the XZ plane of a beam shaping assembly in one specific embodiment. The first lens layer 11 includes m rows and n columns of first microlenses 111, and the second lens layer 12 includes 1 row and n columns of second microlenses 121. In the first lens layer 11, the j-th lens in the i-th column is denoted as ij. The i-th second microlens 121 in the second lens layer 12 is used to shape the light emitted from the i-th column of the first microlenses 111, ensuring that the light emitted from the i-th column of the first microlenses 111 can illuminate the i-th second microlens 121.

[0071] Among them, the optical axis coordinates of each second microlens 121 along the first direction X are different, and the optical axis coordinates of each second microlens 121 along the second direction Y are the same, that is, each Figure 7 The second microlens 121 of the structural unit shown is coaxial along the second direction Y, so that the small line spots formed by multiple structural units in the far field can be superimposed in the far field to form a preset line spot 4, avoiding the small line spots from being misaligned with each other, which would cause the quality of the formed line spot 4 to decrease and affect the accuracy of the optical device.

[0072] It should be noted that since the second microlens 121 is an off-axis microlens, that is, the optical axis of the second microlens 121 is off-axis from its geometric center, the fact that the optical axis of the second microlens 121 has the same coordinate along the second direction Y does not mean that the geometric center of the second microlens 121 has the same coordinate along the second direction Y.

[0073] Specifically, such as Figure 8 and Figure 9As shown, ix represents the coordinate of the geometric center of the i-th second microlens 121 in the second lens layer 12 along the first direction X, iy represents the coordinate of the geometric center of the i-th second microlens 121 in the second lens layer 12 along the second direction Y, ijx represents the coordinate of the geometric center O of the j-th first microlens 111 in the i-th column of the first lens layer 11 along the first direction X, and ijy represents the coordinate of the geometric center O of the j-th first microlens 111 in the i-th column of the first lens layer 11 along the second direction Y. Since the first microlens 111 is an off-axis lens, the coordinates of the optical axis L of the first microlens 111 along the first direction X are different from the coordinates of its geometric center O along the first direction X, and the two have an offset; the coordinates of the optical axis L of the first microlens 111 along the second direction Y are also different from the coordinates of its geometric center O along the second direction Y, and the two have an offset.

[0074] Combination Figure 9 ,ij△x is the offset of the optical axis L of the j-th first microlens 111 in the i-th column of the first lens 11 in the first layer of lenses 11 relative to its geometric center O in the first direction X,ij△y is the offset of the optical axis L of the j-th first microlens 111 in the i-th column of the first layer of lenses 11 in the second direction Y, andi△y is the offset of the optical axis of the i-th second microlens 121 relative to the optical axis of the i-th column of the first microlens 111 in the second direction Y.

[0075] according to Figure 9 As shown in the attached figures and the projection relationship between the first microlens 111 and the second microlens 121, the first lens 11 and the second lens 12 satisfy the following relationship:

[0076]

[0077]

[0078] i Δy =0; (3)

[0079] Among them, the focal length of each first microlens 111 is the same and is h1. Along the third direction Z, the distance between the i-th second microlens 121 in the second layer lens 12 and the first rear surface 111b is h2.

[0080] Therefore, for Figure 7 For the structural unit shown, its first microlens 111 and second microlens 121 need to satisfy the constraints mentioned above, so that the small line spots formed in the far field after being shaped by each structural unit can be superimposed to form the line spot 4 mentioned above.

[0081] In one specific embodiment, according to the principle of diffraction, the diffraction limit of the line spot 4 formed in the far field by the light rays emitted from the second microlens 121 is... Wherein, the aperture of the second microlens 121 is dx, and the divergence angle of the far-field line spot 4 formed by the beam shaping component is θx, satisfying:

[0082]

[0083] Where λ is the wavelength of light.

[0084] Therefore, based on the divergence angle θx of the aforementioned line spot 4, the size range of the aperture dx of the second microlens 121 can be obtained. The larger the aperture of the second microlens 121, the smaller the divergence angle of the line spot 4. When a line spot 4 with a small divergence angle is required, the aperture of the second microlens 121 cannot be too small. For example, the divergence angle of the line spot 4 can be 0.2°.

[0085] from Figure 3-7 It can be seen that the aperture of the second microlens 121 is larger than that of the first microlens 121.

[0086] In one specific embodiment, the aperture of the first microlens 111 is less than or equal to 32 μm. The aperture of the first microlens 111 is not too large, so that the volume of the beam shaping component is not too large.

[0087] In the above embodiments, as Figure 1 , Figure 2 and Figure 10 As shown, Figure 10 for Figure 1 and Figure 2 A schematic diagram of the structure of the light-emitting device 2 in a specific embodiment is shown. In this embodiment, the light-emitting device 2 may include multiple point light sources 21, each point light source 21 being arrayed along a first direction X and a second direction Y, and each point light source 21 corresponding to a first microlens 111. When the optical device is working, the light emitted from each point light source 21 can be incident on the first microlens 111 of the beam shaping component, thereby forming a line light spot 4 in the far field under the shaping effect of the first microlens 111 and the second microlens 121. That is, the beam shaping component can transform the arrayed point light of the point light sources 21 into a line light spot 4.

[0088] The number of point light sources 21 is the same as the number of first microlenses 111, and they correspond one-to-one. Therefore, one second microlens 121 corresponds to one row of point light sources 21.

[0089] Specifically, the light-emitting device 2 can be a vertical-cavity surface-emitting laser (VCSEL). This device is a semiconductor in which the laser beam is emitted perpendicularly from the top surface, unlike edge-emitting lasers which are typically made from cut, individual chips and emit from the edges. Of course, the light-emitting device 2 can also be other types of light-emitting devices; this application does not limit the type or structure of the light-emitting device.

[0090] In one specific embodiment, a row of point light sources 21 illuminates... Figure 7 When a structural unit is shown, under the shaping effect of the structural unit, a small line spot can be formed in the far field. When the optical axis of the second microlens 121 and the coordinates of the corresponding column of point light sources 21 along the first direction X are the same, it can prevent the multiple small line spots formed by each structural unit from deviating from each other along the first direction X, so that the small line spots can be superimposed in the far field along the first direction X to form a line spot 4 and improve the quality of the line spot 4.

[0091] Specifically, such as Figure 10 As shown, along the first direction X, the distance L1 between adjacent point light sources 21 satisfies: 1 ≤ L1 ≤ 5 mm, and / or, along the second direction Y, the distance L2 between adjacent point light sources 21 satisfies: 0.02 mm ≤ L2 ≤ 0.1 mm. For example, L1 can specifically be 1 mm, 2 mm, 2.5 mm, 4 mm, 5 mm, etc., and L2 can specifically be 0.02 mm, 0.05 mm, 0.07 mm, 0.08 mm, 0.1 mm, etc.

[0092] like Figure 8 As shown, the distance between the geometric centers of adjacent first microlenses 111 along the first direction X is h3, and the distance between the geometric centers of adjacent first microlenses 111 along the second direction Y is h4. Since the point light source 21 corresponds one-to-one with the first microlenses 111, h3 = L1, h4 = L2. Therefore, 1 ≤ h3 ≤ 5 mm, and / or 0.02 mm ≤ h4 ≤ 0.1 mm. For example, h3 can specifically be 1 mm, 2 mm, 2.5 mm, 4 mm, 5 mm, etc., and h4 can specifically be 0.02 mm, 0.05 mm, 0.07 mm, 0.08 mm, 0.1 mm, etc.

[0093] The distance h3 between the geometric centers of adjacent first microlenses 111 along the first direction X and the distance L1 between adjacent point light sources 21 along the first direction X are related to the divergence angle of the far-field line spot 4. The larger L1 and h3 are, the smaller the divergence angle of the far-field line spot 4. However, if L1 and h3 are too large, it will lead to an excessively large volume of the beam shaping component. Therefore, the values ​​of L1 and h3 can be selected by comprehensively considering both the divergence angle of the required line spot 4 and the volume of the beam shaping component.

[0094] When the distance h4 between the geometric centers of adjacent first microlenses 111 along the second direction Y and the distance L2 between adjacent point light sources 21 are small, the overall volume of the beam shaping component can be reduced, thereby reducing the volume of the optical device.

[0095] In one specific embodiment, such as Figure 10 As shown, the wavelength of the light emitted by the point light sources 21 distributed in the array can be 940nm, the divergence angle is ±12°, and the spacing L1 between adjacent point light sources 21 along the first direction X is 1.6mm, the spacing L2 between adjacent point light sources 21 along the second direction Y is 0.04mm, and there are 300×8 point light sources 21 in this embodiment. This array of point light sources cooperates with the beam shaping component described above, and the beam shaping component includes 300×8 first microlenses 111 and 8 second microlenses 121. The spacing h3 between the geometric centers of adjacent first microlenses 111 along the first direction X is 1.6mm, the spacing h4 between the geometric centers of adjacent first microlenses 111 along the second direction Y is 0.04mm, and the optical axis of the second microlens 121 is the same as the coordinate of the corresponding column of point light sources 21 along the first direction X. Meanwhile, when each of the first microlenses 111 and the second microlenses 121 satisfies the constraint relationship of the above formulas (1), (2), and (3), a line spot 4 with a divergence angle of 0.2° can be formed in the far field.

[0096] The optical devices described in the above embodiments can be lidar transmitters, for example, lidar transmitters can be used for distance measurement in automobiles. In other embodiments, the optical devices described in this application can also be laser projectors.

[0097] In summary, existing technologies for forming linear light spots involve arranging light sources in a line and then using a large lens to shape the light emitted from these sources. This method results in a large lens size and weight. To address this technical problem, the light-emitting device provided in this application forms a linear light spot using an array of distributed point light sources and a beam shaping component. The beam shaping component transforms the light emitted from the array of point light sources into a far-field linear light spot. Furthermore, because the beam shaping component is implemented using a first microlens and a second microlens, its size and weight are both relatively small. Additionally, the constraint relationship and surface shape of the first and second microlenses in this application embodiment result in a small divergence angle of the formed linear light spot (e.g., less than or equal to 0.2°).

[0098] The above descriptions are merely specific implementations of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of this application should be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A beam shaping assembly, characterized by, The light beam shaping assembly comprises a first layer of lenses and a second layer of lenses, the first layer of lenses comprises a plurality of first microlenses, each of the first microlenses is arrayed along a first direction and a second direction, the second layer of lenses comprises a plurality of second microlenses, each of the second microlenses is arrayed along the first direction, each of the second microlenses corresponds to an array of the first microlenses along the second direction, the first layer of lenses and the second layer of lenses are arrayed along a third direction; The first microlens has a first front surface and a first back surface along the third direction, the second microlens has a second front surface and a second back surface along the third direction, the first layer of lenses is used for collimating and deflecting the light emitted by the light emitting device, so that the light emitted from the first back surface can irradiate the second front surface, the second layer of lenses is used for deflecting and collimating the light irradiating the second front surface, so as to form a line light spot in the far field.

2. The optical beam shaping assembly of claim 1, wherein, The optical axis of the first microlens deviates from the geometric center thereof, and the optical axis of the second microlens deviates from the geometric center thereof.

3. The optical beam shaping assembly of claim 1, wherein, The first front surface is a free-form surface, the first back surface is a plane, and the second front surface and the second back surface are both free-form surfaces.

4. The optical beam shaping assembly of claim 3, wherein, The first front surface, the second front surface, and the second back surface are any one of a spherical surface, a parabolic surface, and a toric surface.

5. The optical beam shaping assembly of claim 1, wherein, The first microlens is an off-axis aspheric lens, and the second microlens is a far-field lens.

6. The beam shaping assembly of any of claims 1-5, wherein, The first layer of lenses comprises m rows and n columns of first microlenses, the second layer of lenses comprises 1 row and n columns of second microlenses, in the first layer of lenses, the jth first microlens in the ith column is ij, and the ith second microlens in the second layer of lenses is used for shaping the light emitted from the first microlenses in the ith column; The coordinates of the optical axes of the second microlenses along the first direction are different from each other, and the coordinates of the optical axes of the second microlenses along the second direction are the same.

7. The optical beam shaping assembly of claim 6, wherein, The first layer of lenses and the second layer of lenses satisfy the following relationship: i Δy ＝0； wherein ix is the coordinate of the geometric center of the ith second microlens along the first direction, iy is the coordinate of the geometric center of the ith second microlens along the second direction, ijx is the coordinate of the geometric center of the jth first microlens in the ith column along the first direction, and ijy is the coordinate of the geometric center of the jth first microlens in the ith column along the second direction; ij△x is the offset of the optical axis of the jth first microlens in the ith column relative to the geometric center thereof in the first direction, ij△y is the offset of the optical axis of the jth first microlens in the ith column relative to the geometric center thereof in the second direction, and i△y is the offset of the optical axis of the ith second microlens relative to the optical axis of the first microlenses in the ith column in the second direction; The focal lengths of the first microlenses are the same and are h1, and the distance between the ith second microlens in the second layer of lenses and the first back surface along the third direction is h2.

8. The optical beam shaping assembly of claim 5, wherein, The spacing h3 between the geometric centers of adjacent first microlenses along the first direction satisfies 1≤h3≤5 mm, and / or the spacing h4 between the geometric centers of adjacent first microlenses along the second direction satisfies 0.02 mm≤h4≤0.1 mm.

9. The optical beam shaping assembly of claim 5, wherein, An aperture of each of the second microlenses is dx, a divergence angle of a far-field line spot formed by the beam shaping assembly is θx, and the following is satisfied: where λ is a wavelength of light.

10. The optical beam shaping assembly of claim 5, wherein, An aperture of the first microlenses is less than or equal to 32 μm.

11. An optical device, characterized by The optical device comprises: a housing; a light emitting device disposed in the housing; a beam shaping assembly mounted to the housing; wherein the beam shaping assembly is any one of the beam shaping assemblies of claims 1-10.

12. The optical device of claim 11, wherein, The light emitting device comprises a plurality of point light sources, the plurality of point light sources are arrayed along a first direction and a second direction, and the point light sources and the first microlenses correspond one-to-one.

13. The optical device of claim 12, wherein, An optical axis of the second microlenses and a column of point light sources corresponding to the second microlenses have the same coordinate along the first direction.

14. The optical device of claim 12, wherein, Along the first direction, a distance L1 between adjacent point light sources satisfies 1≤L1≤5 mm, and / or along the second direction, a distance L2 between adjacent point light sources satisfies 0.02 mm≤L2≤0.1 mm.

15. The optical device of any of claims 11-14, wherein, The optical device is a laser radar transmitter.

16. The optical device of any one of claims 11-14, wherein, The optical device is a laser projector.

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