Laser and projection system

Abstract

A laser includes a housing (100), a plurality of laser chip assemblies (200), and a shaping and homogenizing member (300). The shell (100) comprises a bottom plate (101) and a side wall (102). The side wall (102) is arranged on the bottom plate (101). The plurality of laser chip assemblies (200) are disposed on the base plate (101). The shaping and homogenizing part (300) is connected with the side wall (102) and located on the side, away from the bottom plate (101), of the side wall (102). The shaping and homogenizing component (300) and the shell (100) jointly define a first closed space (103). A plurality of laser chip assemblies (200) are located in the first enclosed space (103). The shaping and homogenizing component (300) is located on an emergent light path of the laser chip assembly (200) and is configured to receive a laser beam emitted by the laser chip assembly (200) and perform collimation and diffraction homogenization on the received laser beam.

Description

Laser and projection systems

[0001] This application claims priority to the Chinese patent application with application number 202211377343.0 filed on November 4, 2022, and the Chinese patent application with application number 202222692471.6 filed on October 13, 2022, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a laser and a projection system. Background Art

[0003] With the development of laser projection technology, projection equipment has gradually become a common tool in people's daily lives and work. The light source in a projection device can emit laser light of various colors, which form the projected image. Furthermore, the higher the symmetry of the laser light emitted by the light source, the better the mixing effect and the better the display quality of the projected image.

[0004] Summary of the Invention

[0005] On the one hand, a laser is provided, comprising a housing, a plurality of laser chip assemblies, and a shaping and homogenizing component. The housing comprises a base plate and a side wall. The side wall is disposed on the base plate. The plurality of laser chip assemblies are disposed on the base plate. The shaping and homogenizing component is connected to the side wall and is located on a side of the side wall facing away from the base plate. The shaping and homogenizing component and the housing together define a first enclosed space. The plurality of laser chip assemblies are located in the first enclosed space. The shaping and homogenizing component is located on the outgoing light path of the laser chip assembly and is configured to receive the laser beam emitted by the laser chip assembly and to collimate and diffract and homogenize the received laser beam.

[0006] On the other hand, a projection system is provided, comprising at least one laser as described in any of the above embodiments, a light modulation component located on the light output side of the laser, and a projection lens located on the light output side of the light modulation component. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0008] FIG1 is a graph illustrating an intensity distribution of a laser beam according to some embodiments;

[0009] FIG2 is a cross-sectional view of a laser according to some embodiments;

[0010] FIG3 is a perspective view of a housing according to some embodiments;

[0011] FIG4 is a cross-sectional view of another laser according to some embodiments;

[0012] FIG5 is a structural diagram of a diffractive optical element according to some embodiments;

[0013] FIG6 is a graph showing laser diffraction efficiency according to some embodiments;

[0014] FIG7 is a structural diagram of a plane reflector according to some embodiments;

[0015] FIG8 is a cross-sectional view of yet another laser according to some embodiments;

[0016] FIG9 is a cross-sectional view of yet another laser according to some embodiments;

[0017] FIG10 is a cross-sectional view of yet another laser according to some embodiments;

[0018] FIG11 is a cross-sectional view of yet another laser according to some embodiments;

[0019] FIG12 is a cross-sectional view of yet another laser according to some embodiments;

[0020] FIG13 is a cross-sectional view of yet another laser according to some embodiments;

[0021] FIG14 is a cross-sectional view of yet another laser according to some embodiments;

[0022] FIG15 is a structural diagram of a projection system according to some embodiments;

[0023] FIG16 is a structural diagram of another projection system according to some embodiments;

[0024] FIG17 is a perspective view of yet another laser according to some embodiments;

[0025] FIG18 is a cross-sectional view of yet another laser according to some embodiments;

[0026] FIG19 is a top view of a laser chip assembly of yet another laser according to some embodiments;

[0027] FIG20 is a front view of a laser chip assembly of yet another laser according to some embodiments;

[0028] FIG21 is a side view of another laser chip assembly of yet another laser according to some embodiments;

[0029] FIG22 is a schematic diagram of diffraction orders of a reflective diffraction grating according to some embodiments;

[0030] FIG23 is a wavelength distribution diagram of a laser chip assembly after wavelength tuning of another laser according to some embodiments;

[0031] 24 is a cross-sectional view of yet another laser according to some embodiments. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, rather than all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0033] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0034] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0035] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can mean fixed connection, detachable connection, or integration; it can be directly connected or indirectly connected through an intermediate medium.

[0036] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0037] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0038] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0039] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0040] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0041] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0042] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0043] Projection display is a method or device that uses a flat image to control a light source, utilizing an optical system and projection space to magnify the image and display it on a screen. With the development of projection display technology, projection display has gradually been applied to business activities, conferences and exhibitions, scientific education, military command, traffic management, centralized monitoring, advertising and entertainment, and other fields. Its advantages, such as large display size and clear display, also meet the requirements of large-screen display.

[0044] The most commonly used projection system at present is the Digital Light Processing (DLP) architecture, which uses a digital micromirror device (DMD) as its core component. The light emitted by the projection light source is incident on the DMD to produce an image. The output light of the image produced by the DMD is then incident on the projection lens, which forms an image and finally receives it on the projection screen.

[0045] Projection light sources typically use MCL (Multi-Chip LD, MCL for short) lasers. MCL lasers are highly integrated, facilitating the miniaturization of laser light sources. MCL lasers typically incorporate multiple laser chips, and some MCL lasers can simultaneously include three-primary-color laser chips (i.e., three laser chips, each capable of emitting a primary color). Therefore, using an MCL laser can achieve the emission of three primary colors.

[0046] FIG. 1 is a graph illustrating an intensity distribution of a laser beam according to some embodiments.

[0047] As shown in Figure 1 (a), the energy distribution of the light beam emitted by the laser chip in the MCL laser is Gaussian. The Gaussian distribution shows a trend of higher light intensity at the center and a sharp decrease in light intensity at the edge. Laser chips with this energy distribution cannot meet the requirements of uniform illumination.

[0048] To achieve uniform illumination, the laser light emitted by the MCL laser needs to be converted into a flat-top beam. As shown in Figure 1(b), the flat-top beam has uniform light intensity at all positions, meeting the illumination requirements of the projection system.

[0049] In some embodiments, a diffuser is placed on the light-emitting side of the MCL laser to homogenize the beam emitted by the MCL laser, thereby homogenizing the intensity of the laser beam. However, the effect of using a diffuser to homogenize the beam is not ideal. The beam intensity will change from that shown in Figure 1 (a) to that shown in Figure 1 (c), where the energy distribution of the beam shows a trend of high brightness at the center and low brightness at the edges.

[0050] In some embodiments, the light intensity distribution of the laser beam can be made more uniform by increasing the divergence angle of the laser beam emitted by the MCL laser. However, this will result in a significant loss of edge energy.

[0051] Furthermore, projection systems require light guides, fly-eye lenses, and other light-homogenizing components on the light output side of the projection light source to homogenize the light. However, directing light from a laser source into a narrow light guide results in significant energy loss. To achieve a certain degree of uniformity, the light guide must be extended to at least 30 mm, which increases the length of the optical engine and hinders the miniaturization of the projection system.

[0052] Based on this, some embodiments of the present disclosure provide a projection system 10, which includes a laser 1. The laser 1 can effectively homogenize the intensity distribution of the laser beam, eliminating the need for a light pipe in the projection system 10, thereby facilitating a compact design of the projection system 10.

[0053] FIG. 2 is a cross-sectional view of a laser according to some embodiments; FIG. 3 is a perspective view of a housing according to some embodiments.

[0054] In some embodiments, as shown in FIG. 2 and FIG. 3 , the laser 1 includes a housing 100 , a plurality of laser chip assemblies 200 , and a shaping and homogenizing component 300 .

[0055] The housing 100 is configured to house and encapsulate the laser chip assembly 200. The housing 100 includes a base plate 101 and a sidewall 102. The sidewall 102 is annular and disposed on the base plate 101, substantially perpendicular thereto. The base plate 101 and the sidewall 102 together define a housing cavity 13.

[0056] In some embodiments, the bottom plate 101 and the sidewalls 102 may be made of the same material. For example, the bottom plate 101 and the sidewalls 102 may be made of oxygen-free copper or Kovar metal.

[0057] A plurality of laser chip assemblies 200 are fixedly disposed on the base plate 101 and located in the accommodating cavity 13 .

[0058] In some embodiments, the laser chip assembly 200 includes a laser chip 201 and a heat sink 202. The heat sink 202 is disposed on the base plate 101, and the laser chip 201 is disposed on the heat sink 202. The heat sink 202 is configured to dissipate heat from the laser chip 201. The laser chip 201 is configured to emit a laser beam.

[0059] In some embodiments, the laser chip 201 and the heat sink 202 may be welded using a high-precision eutectic welding machine to form a laser chip assembly, also referred to as a chip on submount (COS) assembly.

[0060] In some embodiments, the heat sink 202 is a metal material. It is understood that the heat sink 202 can also be made of other materials with good thermal conductivity, and the present disclosure does not limit this.

[0061] The shaping and homogenizing component 300 is connected to the sidewall 102 and is located on the side of the sidewall 102 facing away from the base plate 101. The side of the sidewall 102 facing away from the base plate 101 is open to form an opening. The shape of the shaping and homogenizing component 300 is compatible with the shape of the opening. The shaping and homogenizing component 300 can be connected to the housing 100 through adhesive, welding, or other methods, and the shaping and homogenizing component 300 can be used to block the opening. In this way, the shaping and homogenizing component 300 and the housing 100 can jointly define a first enclosed space 103. In addition, the laser chip assembly 200 is disposed in the enclosed first enclosed space 103, thereby ensuring that the laser chip assembly 200 is well protected.

[0062] In some embodiments, the shaping and homogenizing component 300 is located in the outgoing light path of the laser chip assembly 200 and is configured to receive the laser beam emitted from the laser chip assembly 200 and collimate and diffract and homogenize the received laser beam. In this way, the laser beam emitted from the laser chip assembly 200, which exhibits a Gaussian distribution with high intensity in the middle and low intensity at the edges, can be shaped by the shaping and homogenizing component 300 into a flat-top beam with uniform intensity distribution.

[0063] It can be understood that a flat-top beam with uniform intensity distribution as a projection light source meets the lighting requirements of the projection system 10, so there is no need to set up components such as light pipes, fly-eye lenses, and diffusers in the projection system 10. In this way, energy loss caused by excessive components can be reduced and the structural design of the projection system 10 can be simplified.

[0064] In addition, the shaping and homogenizing component 300 can replace the sealing glass of the projection system in the related art. The shaping and homogenizing component 300 and the shell form a first closed space 103 to seal the laser chip assembly, thereby realizing the integration of the optical element functions inside the laser 1, which is conducive to the miniaturization design of the laser 1 and the projection system 10.

[0065] The structure of the shaping and homogenizing component 300 will be described in detail below.

[0066] 4 is a cross-sectional view of another laser according to some embodiments.

[0067] In some embodiments, as shown in FIG. 4 , the shaping and homogenizing component 300 includes a plurality of first collimating portions 301 and a diffractive portion 302 .

[0068] Multiple first collimating sections 301 are located on a side of the shaping and homogenizing component 300 close to the laser chip assembly 200. Each of the multiple first collimating sections 301 is provided corresponding to a laser chip assembly 200. The first collimating section 301 is configured to receive the laser beam emitted by the corresponding laser chip assembly 200 and collimate the received laser beam.

[0069] The diffraction section 302 is located on a side of the first collimating section 301 facing away from the laser chip assembly 200. The laser beam, collimated by the first collimating section 301, is incident on the diffraction section 302. The diffraction section 302 is configured to diffract and homogenize the received collimated laser beam, thereby uniformly distributing the energy of the laser beam. Specifically, the diffraction section 302 shapes the laser beam from a Gaussian distribution into a flat-top beam with uniform energy distribution, thereby meeting the illumination requirements of the projection system 10.

[0070] FIG5 is a structural diagram of a diffractive optical element according to some embodiments.

[0071] In some embodiments, as shown in FIG5 , the diffractive portion 302 includes a diffractive optical element (DOE) 310. The diffractive optical element 310 includes a substrate 311 and a plurality of diffractive structures 312 disposed on the substrate 311. The diffractive structures 312 are arranged in a two-dimensional matrix. The diffractive structures 312 are configured to diffract a laser beam passing through the diffractive structures 312 and generate interference at a certain distance, thereby forming a specific light intensity distribution.

[0072] In some embodiments, the two-dimensionally distributed diffraction structure 312 can be formed by etching using a micro-nano etching process. Each diffraction structure 312 can have a specific morphology, size, refractive index, etc., so that the laser wavefront phase distribution can be finely controlled.

[0073] For example, the morphology, size, refractive index, etc. of each diffraction structure 312 can be designed according to parameters such as the wavelength, beam aperture, beam mode, and near-field intensity distribution of the incident laser beam, and the morphological characteristics of the microstructure can be obtained through computer simulation to achieve homogenization control.

[0074] It can be understood that, as shown in Figure 1, through the special design of each diffraction structure 312 of the diffraction part 302, the laser beam with Gaussian distribution shown in (a) of Figure 1 can be homogenized into a flat-top beam with uniform energy distribution as shown in (b) of Figure 1 after passing through the diffraction part 302, thereby meeting the lighting requirements in the projection system 10.

[0075] In some embodiments, the laser beam shaping effect of the diffraction unit 302 can be used to convert the laser beam incident on the diffraction unit 302 into a rectangular light spot having a shape and size that matches the DMD in the projection system 10. It will be appreciated that irradiating the rectangular light spot onto the DMD for projection display eliminates the need for adding a shaping component specifically for adjusting the light spot shape to the projection system 10, thereby simplifying the structure of the projection system 10.

[0076] In some embodiments, the diffraction structure 312 of the diffraction portion 302 can be designed as multiple single structures, such as the stepped structure shown in FIG5 . In some embodiments, the diffraction portion 302 can include multiple diffraction structures 312 of different shapes. For example, the diffraction structure 312 can include a microstructure with a diffraction homogenization effect, such as a sawtooth structure, a trapezoidal structure, an inclined rectangular structure, or a stepped structure. It should be noted that the structure of the diffraction structure 312 can be configured according to actual needs and is not limited in this disclosure.

[0077] In some embodiments, the diffraction efficiency of the diffractive optical element 310 satisfies formula (1):

[0078] In formula (1), η is the diffraction efficiency; λ is the wavelength of the laser; θ is the incident angle of the laser into the diffraction optical element; m is the diffraction order; c is the speed of light in vacuum; It is a function of the laser wavelength λ and the incident angle θ, and its form depends on the structure of the diffractive optical element. The diffraction efficiency η is a decreasing function of the incident angle θ.

[0079] FIG. 6 is a graph illustrating laser diffraction efficiency according to some embodiments.

[0080] In some embodiments, as shown in FIG6 , the abscissa represents the incident angle θ (incident angle) of the laser beam entering the diffractive optical element 310, and the ordinate represents the diffraction efficiency (diffraction efficiency) of the incident laser beam. For example, laser beams having wavelengths of 403 nm, 405 nm, and 407 nm are incident on the diffractive optical element 310, and diffraction efficiency curves are obtained after the laser beams pass through the diffractive optical element 310, respectively.

[0081] As shown in Figure 6, the three laser beams of different wavelengths sequentially enter the diffractive optical element 310 at varying angles of incidence, with the diffraction efficiency of the three laser beams decreasing as the angle of incidence increases. Therefore, to improve the diffraction efficiency of the laser beams passing through the diffractive optical element 310 and thus increase the brightness of the projection light source, it is necessary to ensure that the laser beams enter the diffractive optical element 310 at relatively low angles of incidence.

[0082] It can be understood that in some embodiments of the present disclosure, a plurality of first collimating portions 301 are provided on the light incident side of the diffraction portion 302, and the plurality of first collimating portions 301 collimate the plurality of laser light beams incident to the plurality of first collimating portions 301, thereby reducing the divergence angles of the plurality of laser light beams and reducing the difference in incident angles between the plurality of laser light beams. In this way, the collimated plurality of laser light beams are incident to the diffraction portion 302 in relatively parallel propagation directions, thereby simplifying the design difficulty of the diffraction portion 302 and improving the diffraction efficiency of the diffraction portion 302.

[0083] In some embodiments, as shown in FIG. 4 , the laser further includes a plurality of plane mirrors 400 .

[0084] A plurality of plane reflectors 400 are located within the housing 100. Each plane reflector 400 corresponds to at least one laser chip assembly 200 and is disposed on the light-emitting side of the corresponding laser chip assembly 200. The plane reflector 400 includes a flat first reflective surface 410 facing the light-emitting side of the corresponding laser chip assembly 200 and configured to receive at least one laser beam emitted by the corresponding laser chip assembly 200 and reflect the received laser beam toward the first collimating portion 301.

[0085] For example, the plane reflector 400 is disposed on the bottom plate 101 of the housing 100 , and the first reflective surface 410 is disposed opposite to the corresponding at least one laser chip assembly 200 , which is not limited in the present disclosure.

[0086] FIG. 7 is a structural diagram of a plane reflector according to some embodiments.

[0087] In some embodiments, as shown in FIG7 , multiple plane mirrors 400 can be arranged along a first direction X, with any one of the multiple plane mirrors 400 extending along a second direction Y. Multiple laser chip assemblies 200 are arranged in multiple columns along the first direction X and in multiple rows along the second direction Y. In other words, the multiple laser chip assemblies 200 are arranged in an array. In this way, one plane mirror 400 corresponds to multiple laser chip assemblies 200 and can reflect the laser beams emitted by multiple laser chip assemblies 200, thereby reducing the difficulty of manufacturing and installing the plane mirror 400.

[0088] In some embodiments, multiple plane reflectors 400 may also be provided corresponding to multiple laser chip assemblies 200 , that is, each plane reflector 400 is used to reflect a laser beam emitted by a corresponding laser chip assembly 200 , which is not limited in the present disclosure.

[0089] 8 is a cross-sectional view of yet another laser according to some embodiments.

[0090] In some embodiments, as shown in Figures 4 and 8, the shaping and homogenizing component 300 further includes a first substrate 303 and a second substrate 304. The first substrate 303 is located on a side of the sidewall 102 facing away from the bottom plate 101, thereby defining a first enclosed space 103 together with the housing 100. The second substrate 304 is located on a side of the first substrate 303 facing away from the housing 100.

[0091] It should be noted that the material used to make the first substrate 303 and the material used to make the second substrate 304 may be the same or different, and this disclosure does not limit this.

[0092] In some embodiments, a plurality of first collimating portions 301 are disposed on a side surface of a first substrate 303, and a diffractive portion 302 is disposed on a side surface of a second substrate 304. The side surface of the first substrate 303 not provided with the plurality of first collimating portions 301 is aligned with the side surface of the second substrate 304 not provided with the diffractive portion 302. This allows the first collimating portions 301 to be located on the side of the first substrate 303 facing the laser chip assembly 200, while the diffractive portion 302 to be located on the side of the second substrate 304 facing away from the first substrate 303, thereby forming the shaping and homogenizing component 300 shown in FIG. 4 .

[0093] In some embodiments, the shaping and homogenizing component 300 includes multiple first collimating portions 301 and at least one diffractive portion 302. The multiple first collimating portions 301 are disposed on one side surface of a first substrate 303, and the at least one diffractive portion 302 is disposed on at least one side surface of a second substrate 304. The first substrate 303 and the second substrate 304 are spaced apart by a set distance (e.g., a set distance greater than the thickness of the diffractive portion 302) in a direction perpendicular to the base plate 101. The first collimating portions 301 are located on the side of the first substrate 303 facing the laser chip assembly 200, and the at least one diffractive portion 302 is located on the side of the second substrate 304 facing away from the first substrate 303, on the side of the second substrate 304 facing the first substrate 303, or on both sides of the second substrate 304, thereby forming the shaping and homogenizing component 300 shown in FIG. 8 .

[0094] It is understandable that by setting the first substrate 303 and the second substrate 304 apart by a set distance, it is convenient to adjust the arrangement of the diffraction part 302, thereby facilitating enriching the use scenarios of the shaping and homogenizing component 300.

[0095] In some embodiments, as shown in FIG. 4 and FIG. 8 , the first substrate 303 contacts the sidewall 102 to form a first enclosed space 103 , and the second substrate 304 is located on a side of the first substrate 303 facing away from the bottom plate 101 .

[0096] In some embodiments, a second substrate 304 may be provided in contact with the side wall 102 to form a first enclosed space 103 , and the first substrate 303 is located in the first enclosed space 103 and on the side of the second substrate 304 facing the bottom plate 101 , which is not limited in this disclosure.

[0097] 9 is a cross-sectional view of yet another laser according to some embodiments.

[0098] In some embodiments, as shown in FIG9 , the shaping and homogenizing component 300 further includes a substrate 305. The substrate 305 is located on a side of the sidewall 102 facing away from the bottom plate 101 and, together with the housing 100, defines a first enclosed space 103. A plurality of first collimating portions 301 are located on a surface of the substrate 305 facing the laser chip assembly 200, and the diffractive portion 302 is located on a surface of the substrate 305 facing away from the first collimating portions 301.

[0099] The diffraction section 302, substrate 305, and multiple first collimation sections 301 together form an integrated structure that performs both collimation and diffraction homogenization functions. Thus, laser light emitted from the laser chip assembly 200 is first collimated by the first collimation sections 301 before entering the diffraction section 302, where it is diffracted and homogenized, thereby improving the diffraction efficiency of the diffraction section 302.

[0100] It is understandable that making the shaping and homogenizing component 300 into an integrated structure can simplify the internal structure of the laser 1, which is beneficial to reducing the volume of the laser 1 and the projection system 10, and is beneficial to improving the assembly efficiency of the laser 1 and reducing the assembly difficulty.

[0101] In some embodiments, an integrated structure of the substrate 305 and the plurality of first collimating portions 301 can be formed by an injection molding process, and then a plurality of diffraction structures 312 can be made on the surface of the substrate 305 facing away from the first collimating portion 301 by a micro-nano etching process to form the diffraction portion 302, thereby forming an integrated structure having collimation function and diffraction uniformization function.

[0102] In some embodiments, the plurality of first collimating portions 301 may be a plurality of protruding convex lenses or Fresnel lenses formed on the surface of the substrate 305. Each first collimating portion 301 is located on the outgoing light path of a corresponding laser chip assembly 200 and is configured to collimate the laser beam emitted by the corresponding laser chip assembly 200.

[0103] It should be noted that since the laser beam emitted by each laser chip assembly 200 can have different wavelengths and divergence angles, the parameters of each first collimating portion 301 (such as focal length or refractive index, etc.) need to be designed according to the collimation requirements of the output light of the corresponding laser chip assembly 200.

[0104] In some embodiments, the first collimating portion 301 may also adopt other structures, which is not limited in the present disclosure.

[0105] 10 is a cross-sectional view of yet another laser according to some embodiments.

[0106] In some embodiments, as shown in FIG10 , a laser 1 includes a housing 100, multiple laser chip assemblies 200, a shaping and homogenizing component 300, and multiple curved reflectors 500. The curved reflectors 500 are disposed within the housing 100. Each of the multiple curved reflectors 500 corresponds to a laser chip assembly 200 and is located on the light-emitting side of the corresponding laser chip assembly 200. The curved reflectors 500 include a second reflective surface 510, which is a concave surface and is configured to receive a laser beam emitted by the corresponding laser chip assembly 200, collimate the received laser beam, and reflect the collimated laser beam to the diffraction portion 302 in the shaping and homogenizing component 300.

[0107] In some embodiments, the curved reflector 500 is disposed on the bottom plate 101 of the housing 100 , and the second reflective surface 510 is disposed opposite to the corresponding laser chip assembly 200 , which is not limited in the present disclosure.

[0108] It is understandable that the second reflective surface 510 of the curved reflector 500 is designed as a curved surface, so that when the curved reflector 500 receives the divergent light beam emitted by the laser chip assembly 200, it can converge the light beam and adjust it into a parallel collimated light beam, and then reflect the collimated light beam to the diffraction part 302. In this way, multiple curved reflectors 500 can not only replace multiple first collimating parts 301 to collimate the laser beam, but also replace multiple plane reflectors 400 to reflect the collimated light beam to the diffraction part 302. As a result, the first collimating part 301 and the plane reflector 400 can be simplified into one component, further simplifying the structure of the laser 1.

[0109] In some embodiments, according to the collimation requirements of the laser chip assembly 200, the shape of the second reflecting surface 510 of the curved reflector 500 is specifically designed, so that the curved reflector 500 can focus and collimate the fast axis direction of the laser, focus and collimate the slow axis direction of the laser, or focus and collimate the fast axis direction and the slow axis direction of the laser at the same time, which is not limited here.

[0110] In some embodiments, the substrate 305 is located on a side of the sidewall 102 facing away from the bottom plate 101, and together with the housing 100 defines a first enclosed space 103. The diffractive portion 302 is located on a surface of the substrate 305 facing away from the curved reflector 500, or alternatively, the diffractive portion 302 is located on a surface of the substrate 305 facing the curved reflector 500.

[0111] FIG. 11 is a cross-sectional view of yet another laser according to some embodiments; FIG. 12 is a cross-sectional view of yet another laser according to some embodiments.

[0112] In some embodiments, as shown in FIG. 11 and FIG. 12 , the shaping and homogenizing component 300 further includes a plurality of second collimating portions 306 . The plurality of second collimating portions 306 are disposed on the substrate 305 and are configured to further collimate the collimated laser beam from the curved reflector 500 .

[0113] It is understandable that, due to limitations in the manufacturing process, relying solely on a collimating portion (such as the first collimating portion 301 or the second collimating portion 306) or the curved reflector 500 to collimate the laser beam cannot ensure that the collimation of the collimated laser beam meets the requirements of use. Therefore, by providing the curved reflector 500 and the second collimating portion 306 in the laser 1, the laser beam is collimated twice, thereby ensuring that the collimated laser beam meets the requirements of use.

[0114] In some embodiments, the diffraction portion 302 is arranged on the surface of the substrate 305 on the side away from the curved reflector 500, and the second collimation portion 306 is arranged on the surface of the substrate 305 on the side facing the curved reflector 500. In this way, the laser beam emitted by the laser chip assembly 200 can be collimated twice by the curved reflector 500 and the second collimation portion 306, and then enter the diffraction portion 302 with a higher degree of collimation, which is beneficial to improving the diffraction efficiency of the diffraction portion 302.

[0115] In some embodiments, the diffraction portion 302 may also be disposed on the surface of the substrate 305 facing the curved reflector 500 , and the second collimating portion 306 may be disposed on the surface of the substrate 305 facing away from the curved reflector 500 .

[0116] In some embodiments, the second collimating portion 306 may be a convex lens or a Fresnel lens, which is not limited in the present disclosure.

[0117] 13 is a cross-sectional view of yet another laser according to some embodiments.

[0118] In some embodiments, the laser 1 further includes a support portion 600 and a sealing glass 700. Hereinafter, the structure of the laser 1 will be described by taking the laser 1 shown in FIG13 as an example.

[0119] As shown in FIG13 , support portion 600 is disposed on the inner wall of sidewall 102 and extends along the circumference of sidewall 102. Sealing glass 700 is disposed on support portion 600 and seals support portion 600. Bottom plate 101, a portion of sidewall 102, support portion 600, and sealing glass 700 collectively define a second enclosed space 104.

[0120] In some embodiments, the support portion 600 and the side wall 102 may be an integral structure.

[0121] In some embodiments, the support portion 600 may be fixed to the inner wall of the side wall 102 by a welding process such as eutectic welding.

[0122] In some embodiments, the support portion 600 may be fixed to the inner wall of the side wall 102 in various other ways, which are not limited here.

[0123] In some embodiments, the sealing glass 700 can be connected and fixed to the support portion 600 using a welding process such as eutectic welding, thereby ensuring that the airtightness of the second enclosed space 104 meets the design requirements of the laser 1.

[0124] It is understandable that the laser chip 201 will generate a lot of heat during the light-emitting process, causing the temperature of the air around the laser chip 201 to rise. The high-temperature air reacts with the water and oxygen in the air, which can easily affect the laser chip 201 and reduce the service life of the laser chip 201. Therefore, the laser chip 201 can be protected by encapsulating the laser chip 201 in a closed environment with a low water and oxygen concentration (such as the second closed space 104).

[0125] In some embodiments, the shaping and homogenizing component 300 is fixedly connected to the housing 100 by a welding process such as eutectic welding or adhesive.

[0126] In some embodiments, the shaping and homogenizing component 300 may be fixedly connected to the housing 100 by adhesive.

[0127] It is understandable that during the installation process of the laser 1, the position of the shaping and homogenizing component 300 needs to be frequently moved so that the diffraction portion 302 and the first collimating portion 301 (or the second collimating portion 306) can collimate and homogenize the laser beam emitted by the corresponding laser chip assembly 200, thereby improving the optical performance of the laser 1. In this case, if a welding process is used to fix the shaping and homogenizing component 300 to the housing 100, it is necessary to pre-plate a metal coating for welding at the welding position. Therefore, when the amplitude of the position of the shaping and homogenizing component 300 is large, the actual welding position will not correspond to the preset welding position, which may cause welding failure and further affect the sealing performance and structural stability of the laser 1.

[0128] Therefore, compared with the welding method, the method of fixing the shaping and leveling component 300 to the housing 100 by adhesive is simpler and easier to operate.

[0129] In some embodiments, the substrate 305 (or the first substrate 303 and the second substrate 304) can be connected to the housing 100 by adhesive in a vacuum environment or an inert gas environment, thereby reducing the water and oxygen concentration in the first enclosed space 103 and protecting the laser chip.

[0130] However, since the laser chip 201 generates a lot of heat during its light-emitting process, the high-temperature air will cause the adhesive to volatilize and diffuse into the first enclosed space 103 , reacting with the laser chip 201 , thereby reducing the service life of the laser chip 201 .

[0131] In this case, by disposing the support portion 600 and the sealing glass 700 within the first enclosed space 103 and welding the sealing glass 700 to the support portion 600 by eutectic welding or other methods in a vacuum environment or an inert gas environment, the sealing glass 700, the support portion 600, and the housing 100 together define a second enclosed space 104. It is understood that the second enclosed space 104 has a relatively low water and oxygen concentration, and the second enclosed space 104 is separated from the adhesive by the sealing glass 700 and the support portion 600, thereby preventing the adhesive from volatilizing due to high-temperature air, which is beneficial for extending the service life of the laser chip.

[0132] In some embodiments, the plurality of laser chip assemblies 200 are configured to emit laser beams of the same color, and the diffraction structure 312 of the diffractive optical element 310 can be designed according to the wavelength of the laser beams emitted by the laser chip assemblies 200 .

[0133] 14 is a cross-sectional view of yet another laser according to some embodiments.

[0134] In some embodiments, as shown in FIG. 14 , the plurality of laser chip assemblies 200 includes a plurality of red laser chip assemblies 210 , a plurality of green laser chip assemblies 220 , and a plurality of blue laser chip assemblies 230 .

[0135] A plurality of red laser chip assemblies 210 are arranged in an array to form a red laser chip assembly array, a plurality of green laser chip assemblies 220 are arranged in an array to form a green laser chip assembly array, and a plurality of blue laser chip assemblies 230 are arranged in an array to form a blue laser chip assembly array.

[0136] For example, the plurality of red laser chip assemblies 210 includes eight red laser chip assemblies 210. The eight red laser chip assemblies 210 may constitute a 2×4 red laser chip assembly array.

[0137] For example, the plurality of green laser chip assemblies 220 include four green laser chip assemblies 220. The four green laser chip assemblies 220 constitute a 1×4 green laser chip assembly array.

[0138] For example, the plurality of blue laser chip assemblies 230 include four blue laser chip assemblies 230. The four blue laser chip assemblies 230 may constitute a 1×4 blue laser chip assembly array.

[0139] Thus, the multiple laser chip assemblies 200 can form two rows of red laser chip assemblies 210, one row of green laser chip assemblies 220 and one row of blue laser chip assemblies 230 arranged in sequence, that is, the multiple laser chip assemblies 200 form a 4×4 laser chip assembly array.

[0140] Accordingly, the diffraction portion 302 includes a first diffraction portion 3021, a second diffraction portion 3022, and a third diffraction portion 3023. For example, the first diffraction portion 3021 is located on the light-exiting side of the red laser chip assembly array, the second diffraction portion 3022 is located on the light-exiting side of the green laser chip assembly array, and the third diffraction portion 3023 is located on the light-exiting side of the blue laser chip assembly array.

[0141] The first diffraction portion 3021 is configured to shape and homogenize the laser beam emitted by the red laser chip assembly, the second diffraction portion 3022 is configured to shape and homogenize the laser beam emitted by the green laser chip assembly, and the third diffraction portion 3023 is configured to shape and homogenize the laser beam emitted by the blue laser chip assembly.

[0142] It should be noted that the sizes and divergence angles of the red laser beam emitted by the red laser chip assembly 210, the green laser beam emitted by the green laser chip assembly 220, and the blue laser beam emitted by the blue laser chip assembly 230 may differ. In this case, the parameters of the first diffractive portion 3021, the second diffractive portion 3022, and the third diffractive portion 3023 can be adjusted accordingly based on the light combining optical path, the illumination optical path, and the optical etendue required by the projection system 10 to meet actual application requirements.

[0143] In some embodiments, multiple laser chip assemblies 200 may also be arranged in other forms. It is only necessary to adjust the parameters of the diffractive optical element according to the needs of the laser 1 for the flat-top beam to make the diffractive optical element correspond to the laser chip assembly 200.

[0144] It should be noted that some embodiments of the present disclosure do not limit the arrangement structure of the laser chip assembly 200 and the parameters of the diffractive optical element.

[0145] Some embodiments of the present disclosure further provide a projection system 10. Figure 15 is a structural diagram of a projection system according to some embodiments.

[0146] In some embodiments, as shown in FIG15 , a projection system 10 includes a laser 1 according to any of the above embodiments, a light modulation component 2 located on the light-emitting side of the laser 1, and a projection lens 3 located on the light-emitting side of the light modulation component 2. The output light beam of the laser 1 is a flat-top beam with a uniform intensity distribution.

[0147] After homogenizing and shaping the laser beams, the shaping and homogenizing component 300 in laser 1 combines the laser beams emitted by the multiple laser chip assembly arrays in laser 1 into a single rectangular spot with uniform intensity distribution. This rectangular spot, upon entering the light modulator 2, matches the shape and size of the light modulator 2. This allows the light modulator 2 to directly modulate the rectangular spot emitted by laser 1 and transmit the modulated beam to the projection lens 3, which then outputs and forms an image, projecting the image onto a projection screen or at a predetermined location.

[0148] FIG16 is a block diagram of another projection system according to some embodiments.

[0149] In some embodiments, as shown in FIG. 16 , the projection system 10 further includes a light combining component 4 , which is located between the laser 1 and the light modulation component 2 .

[0150] The laser beams emitted by the multiple laser chip assemblies 200 in the laser 1 can form multiple independent illumination spots. The light combining assembly 4 is configured to combine the multiple independent illumination spots and reflect them at a preset angle to the light modulation component 2. The light modulation component 2 modulates the combined beams and transmits the modulated beams to the projection lens 3. The projection lens 3 images the modulated beams to project an image on a projection screen or at a set position.

[0151] In some embodiments, the projection system 10 includes multiple lasers 1, and the light combining component 4 is further configured to combine laser beams emitted by different lasers 1, which is not limited in the present disclosure.

[0152] In some embodiments, as shown in FIG. 16 , the projection system 10 includes a laser 1 , and the light combining component 4 is configured to combine the laser beams emitted by the laser chip components 200 in the laser 1 .

[0153] For example, the laser 1 includes a red laser chip assembly 210 , a green laser chip assembly 220 and a blue laser chip assembly 230 , and the light combining assembly 4 includes a second reflector 41 , a first light combining mirror 42 and a second light combining mirror 43 .

[0154] The second reflector 41 is located on the outgoing optical path of the blue laser chip assembly 230 and is configured to reflect the blue laser beam emitted by the blue laser chip assembly 230 to the first beam combiner 42. The first beam combiner 42 is located at the intersection of the outgoing optical path of the second reflector 41 and the outgoing optical path of the green laser chip assembly 220, and is configured to transmit the blue laser beam and reflect the green laser beam emitted by the green laser chip assembly 220. The second beam combiner 43 is located at the intersection of the outgoing optical path of the first beam combiner 42 and the outgoing optical path of the red laser chip assembly 210, and is configured to transmit the blue laser beam and the green laser beam and reflect the red laser beam emitted by the red laser chip assembly 210. In this way, the red laser beam, the green laser beam, and the blue laser beam can be combined into a composite beam, which is emitted from one side of the second beam combiner 43 to the light modulation component 2.

[0155] It should be noted that, when the projection system 10 includes a plurality of lasers 1 , the light combining component 4 can be configured with reference to the above light combining principle, which will not be elaborated in this disclosure.

[0156] In some embodiments, as shown in FIG16 , the projection system 10 includes a reflective assembly 5. The reflective assembly 5 is disposed on the light-emitting side of the light-combining assembly 4 and is configured to change the propagation path of the light beam (such as the composite light beam), thereby shortening the length of the projection system 10 and facilitating a miniaturized design of the projection system 10. The reflective assembly 5 includes at least one total reflection prism 51.

[0157] For example, at least one total reflection prism 51 includes a first total reflection prism 511 and a second total reflection prism 512 that are arranged opposite to each other. When the composite light beam is incident on the transmission and reflection surface of the first total reflection prism 511 at a preset angle, the incident angle of the composite light beam meets the total reflection condition of the transmission and reflection surface of the first total reflection prism 511. In this case, the transmission and reflection surface of the first total reflection prism 511 can reflect all of the composite light beam to the light modulation component 2. Then, the light beam modulated by the light modulation component 2 is reflected by the light modulation component 2 to the transmission and reflection surface. At this time, the modulated light beam does not meet the total reflection condition of the transmission and reflection surface, and can be emitted from the transmission and reflection surface to the second total reflection prism 512. The second total reflection prism 512 refracts the modulated light beam so that the modulated light beam can be vertically incident on the projection lens 3.

[0158] In some embodiments, the reflective assembly 5 includes a third reflector. After the composite light beam is incident on the third reflector at a preset angle, the third reflector can reflect the composite light beam to the light modulating component 2 in a direction that satisfies the incident angle of the light modulating component 2. The light modulating component 2 modulates the composite light beam before emitting it toward the projection lens 3.

[0159] In some embodiments, the light modulation component 2 includes a DMD, which is a reflective optical device. The DMD includes multiple fourth reflectors, each of which can be individually driven to deflect. By controlling the deflection angle of the fourth reflectors, the light beam can be modulated and reflected to the projection lens 3.

[0160] In some embodiments, the light modulation component 2 may also include a liquid crystal display (LCD) or a liquid crystal on silicon (LCOS) light valve, etc., which is not limited here.

[0161] In some embodiments, as shown in Figures 15 and 16, the projection system 10 further includes an illumination lens group 6 located between the laser 1 and the light modulation component 2. The illumination lens group 6 is configured to shape and homogenize the composite light beam so that the composite light beam meets the use requirements of the light modulation component 3.

[0162] It is understandable that by providing the illumination lens group 6 in the projection system 10 to further shape and homogenize the composite light beam incident on the light modulation component 2, the projection system 10 can be applied to more usage scenarios.

[0163] In some embodiments, as shown in FIG15 , the illumination lens group 6 is located between the laser 1 and the light modulation component 2. In some embodiments, as shown in FIG16 , the illumination lens group 6 is located between the light combining component 4 and the reflective component 5. In some embodiments, the projection system 10 may include more or fewer optical elements to achieve light beam shaping and homogenization functions or other functions. In this case, the illumination lens group 6 can be configured according to actual needs. The illumination lens group 6 may include one or more lenses, as long as the light beam shaping and homogenization can be achieved, and this disclosure does not limit this.

[0164] It is understood that the laser 1 in the projection system 10 is used to emit laser beams of multiple colors. The display effect of the projected image formed by these laser beams depends on the symmetry, overlap, and light mixing uniformity of the laser beams. Therefore, in the field of laser projection, to achieve higher brightness and higher color gamut coverage, the laser 1 uses three monochromatic laser chips as a full-color laser projection light source. However, when the laser 1 emits three primary color laser beams through the three laser chips, the three primary color laser light source will produce speckle.

[0165] To this end, some embodiments of the present disclosure provide another projection system 10. Projection system 10 includes a reflective diffraction grating that can tune the specific wavelengths of laser beams emitted by multiple laser chip assemblies, thereby enabling different laser chip assemblies to operate at different central wavelengths. Furthermore, by varying the wavelengths of the laser beams emitted by the laser chip assemblies, the coherence between the multiple laser beams is reduced, thereby suppressing the generation of speckle.

[0166] In some embodiments, the projection system 10 may be a holographic projection system. The projection system 10 includes a laser 1 (i.e., a laser light source packaging structure), a projection lens, and a light modulation component. The laser 1 is configured to provide a laser beam of three primary colors. The light modulation component is configured to modulate the laser beam emitted by the laser 1 and transmit the modulated laser beam to the projection lens, which outputs and images the image to project it onto a projection screen or a set position. The projection lens may include multiple lenses to focus and adjust the imaging effect.

[0167] FIG. 17 is a perspective view of yet another laser according to some embodiments; and FIG. 18 is a cross-sectional view of yet another laser according to some embodiments.

[0168] In some embodiments, as shown in FIG. 17 and FIG. 18 , the laser 1 includes a housing 100 and a plurality of laser chip assemblies 200 .

[0169] The housing 100 includes a base plate 101 and sidewalls 102. The sidewalls 102 surround the base plate 101 and together with the base plate 101 define a housing cavity 13. Multiple laser chip assemblies 200 are disposed in the housing cavity 13. The side of the sidewalls 102, away from the base plate 101, is open to form a light outlet. Thus, the multiple laser beams emitted by the multiple laser chip assemblies 200 can be emitted from the light outlet to the exterior of the laser 1.

[0170] In some embodiments, the housing 100 can be made of metal. For example, the housing 100 can be made of copper. As will be appreciated, copper has a high thermal conductivity, which facilitates the conduction of heat generated by the laser chip assembly 200 to the exterior of the housing 100 , thereby reducing the temperature within the housing cavity 13 , improving the luminous performance of the laser chip assembly 200 and extending its service life.

[0171] In some embodiments, the projection system 10 further includes a bracket for fixing the laser 1. As shown in Figure 17, the housing 100 further includes two connecting plates 110. The two connecting plates 110 are disposed on both sides of the bottom plate 101 and are configured to be fixedly connected to the bracket.

[0172] For example, the laser 1 further includes a plurality of connection holes 111. A portion of the plurality of connection holes 111 is disposed on one connection plate 110, while another portion of the plurality of connection holes 111 is disposed on another connection plate 110. A plurality of through holes are disposed on the bracket of the projection system 10 at locations corresponding to the plurality of connection holes 111. Fasteners pass through the connection holes 111 and the corresponding through holes, thereby securing the laser 1 to the bracket and improving the stability of the housing 100.

[0173] In some embodiments, the connection hole 111 may be a bolt hole, or a riveted through hole, etc. In this case, the fastener may be a bolt, a screw, or a rivet, etc.

[0174] In some embodiments, the laser 1 further includes a snap-fit ​​structure, and the laser 1 can be snap-fitted to a bracket of the projection system 10 via the snap-fit ​​structure, which is not limited in the present disclosure.

[0175] The bottom plate 101 is disposed at the bottom of the side wall 102 and is disposed opposite to the light outlet of the housing 100. The bottom plate 101 is configured to carry a plurality of laser chip assemblies 200.

[0176] Multiple laser chip assemblies 200 are arranged in an array on the base plate 101. For example, the multiple laser chip assemblies 200 are arranged in multiple rows and columns on the base plate 101. The multiple laser chip assemblies 200 include multiple red laser chip assemblies 210, multiple green laser chip assemblies 220, and multiple blue laser chip assemblies 230.

[0177] The red laser chip assembly 210 , the green laser chip assembly 220 , and the blue laser chip assembly 230 can emit red laser, green laser, and blue laser, respectively, to form a full-color laser projection light source of the projection system 10 .

[0178] It should be noted that the embodiments in this disclosure are all illustrated using the example of a laser chip assembly 200 emitting blue, green, and red laser light simultaneously. In some embodiments, the laser chip assembly 200 may also emit only any two of the following laser colors: blue, green, and red. This disclosure is not limited to this.

[0179] In some embodiments, laser chip assemblies 200 emitting laser light of the same color are arranged in a column, and all laser chip assemblies 200 in each column of laser chip assemblies 200 are connected in series.

[0180] For example, all laser chip assemblies 200 in each column of laser chip assemblies 200 are connected in series via gold wire. Specifically, the multiple laser chip assemblies 200 are arranged into a red laser chip assembly column, a green laser chip assembly column, and a blue laser chip assembly column. The red laser chip assembly columns, the green laser chip assembly columns, and the blue laser chip assembly columns are arranged alternately, thereby ensuring uniform mixing of the laser beams emitted by the multiple laser chip assemblies 200.

[0181] In some embodiments, as shown in Figures 17 and 18, the plurality of laser chip assemblies 200 are arranged into four laser chip assembly columns, including two red laser chip assembly columns, one green laser chip assembly column, and one blue laser chip assembly column.

[0182] In some embodiments, the plurality of laser chip assemblies 200 may be arranged into five, six, or multiple rows of laser chip assembly columns. Furthermore, the multiple rows of laser chip assembly columns include at least one row of red laser chip assembly columns, at least one row of green laser chip assembly columns, and at least one row of blue laser chip assembly columns.

[0183] In some embodiments, as shown in FIG17 , the laser 1 further comprises a plurality of electrode pins 19 . The plurality of electrode pins 19 are arranged in pairs on both sides of the housing 100 . Each pair of electrode pins 19 corresponds to a column of laser chip assemblies, and each pair of electrode pins 19 includes a positive pin and a negative pin. Each pair of electrode pins 19 is electrically connected to a column of laser chip assemblies, so that the column of laser chip assemblies is electrically connected to an external power source. The external power source is configured to supply power to the plurality of laser chip assemblies 200 so that the plurality of laser chip assemblies 200 emit laser beams.

[0184] For example, four columns of laser chip assemblies correspond to four pairs of electrode pins 19 , and the laser chip assembly 200 is electrically connected to the external power supply through the four pairs of electrode pins 19 .

[0185] 19 is a top view of a laser chip assembly of yet another laser according to some embodiments.

[0186] 18 and 19 , the laser chip assembly 200 includes a laser chip 201, a heat sink 202, a collimating lens 250, and a reflective diffraction grating 260. The laser chip 201 is configured to emit a laser beam.

[0187] The laser chip 201 is mounted on a heat sink 202. An anti-reflection film is applied to the front cavity surface of the laser chip 201, thereby reducing the reflectivity of the front cavity surface of the laser chip 201 to less than 1%. The laser chip 201 is welded to the heat sink 202 using a eutectic process.

[0188] The heat sink 202 is disposed on the base plate 101 and is configured to conduct heat generated by the laser chip 201 when emitting light to the base plate 101, and then conduct heat from the base plate 101 to the sidewalls 102, and dissipate heat outward from the sidewalls 102. For example, the heat sink 202 can be made of materials such as aluminum nitride (AlN) and silicon carbide (SiC).

[0189] In some embodiments, the red laser chip assembly 210 includes a red laser chip, the blue laser chip assembly 230 includes a blue laser chip, and the green laser chip assembly 220 includes a green laser chip. Thus, different laser chips emit laser beams of different colors (e.g., laser beams of the three primary colors), thereby providing a full-color laser projection light source for the light modulation component 2.

[0190] Collimating lens 250 is disposed between laser chip 201 and reflective diffraction grating 260, on the light-emitting side of laser chip 201. Collimating lens 250 is configured to collimate the laser beam and emit the collimated laser beam toward reflective diffraction grating 260. After being collimated by collimating lens 250, the laser beam has a high reflectivity when incident on reflective diffraction grating 260.

[0191] In some embodiments, an antireflection film is provided on the surface of the collimating lens 250 to enhance the collimation effect of the collimating lens 250. The antireflection film is configured to antireflect the full spectrum light beam, or the antireflection film is configured to antireflect the light beam of a preset wavelength band.

[0192] In some embodiments, the collimating lens 250 may be a convex lens, a plano-convex lens, or a Fresnel lens, etc., as long as it can collimate the laser beam, and the present disclosure does not limit this.

[0193] In some embodiments, the collimating lens 250 is a plano-convex lens, that is, the collimating lens 250 includes a convex curved surface and a flat surface, and the convex curved surface and the flat surface are arranged opposite each other. The flat surface is arranged toward the light-emitting side of the laser chip 201, and the convex curved surface is arranged toward the reflective diffraction grating 260. The collimating lens 250 can be a single piece or a split piece, which is not limited in this disclosure. For example, the shape of the convex curved surface can be spherical or aspherical.

[0194] The reflective diffraction grating 260 is disposed on the light-emitting side of the collimating lens 250. The reflective diffraction grating 260 is configured to reflect the laser beam collimated by the collimating lens 250 and adjust the central wavelength of the laser beam so that the laser light emitted by each laser chip 201 has a different central wavelength after being reflected by the reflective diffraction grating 260. This can reduce speckle in the projection system 10, simplify the optical path of the laser 1, and facilitate the miniaturization of the projection system 10 and the laser 1.

[0195] 20 is a front view of a laser chip assembly of yet another laser according to some embodiments.

[0196] In some embodiments, as shown in FIG20 , a reflective diffraction grating 260 includes a first reflector 261, a grating portion 262, and a dispensing portion 263. The grating portion 262 is disposed on a surface of the first reflector 261 facing the collimating lens 250 and is configured to change the phase of a laser beam incident on the grating portion 262. In some embodiments, the grating portion 262 is also configured to change the central wavelength of the laser beam incident on the grating portion 262.

[0197] The glue dispensing portion 263 is disposed on a side of the first reflector 261 close to the base plate 101. Glue is applied to the glue dispensing portion 263 to securely connect the first reflector 261 to the base plate 101. For example, the glue dispensing portion 263 is a glue dispensing groove, etc., which is not limited in this disclosure.

[0198] In some embodiments, the first reflector 261 may also be fixed to the base plate 101 by welding or other methods.

[0199] 21 is a side view of another laser chip assembly of yet another laser, according to some embodiments.

[0200] In some embodiments, as shown in FIG. 21 , the reflective diffraction grating 260 includes a right-angle reflecting prism 264 and a grating portion 262 .

[0201] The bottom surface of the right-angle reflecting prism 264 is fixedly connected to the base plate 101. For example, the bottom surface of the right-angle reflecting prism 264 is fixedly connected to the base plate 101 by bonding, clamping, or the like. The grating portion 262 is formed on the inclined surface of the right-angle reflecting prism 264 (i.e., the surface of the reflecting prism 264 facing the collimating lens 250). For example, the grating portion 262 can be directly formed on the inclined surface of the right-angle reflecting prism 264 using laser micromachining or photolithography technology.

[0202] FIG22 is a schematic diagram illustrating diffraction orders of a reflective diffraction grating according to some embodiments.

[0203] In some embodiments, as shown in FIG22 , the grating portion 262 of the reflective diffraction grating 260 includes a plurality of sub-grating portions 2621. The plurality of sub-grating portions 2621 are periodically arranged at equal intervals and have parallel lines, thereby being able to change the phase of the laser beam. For example, the plurality of sub-grating portions 2621 include multi-level sub-grating portions 2621, such as a 0-level sub-grating portion, a 1-level sub-grating portion, and the like. The sub-grating portions 2621 of different levels are configured to receive laser beams of different wavelengths, and the laser beams undergo different levels of diffraction on the sub-grating portions 2621 of different levels. In addition, the laser chip 201 can emit laser beams of different wavelengths, and the optical powers of the laser beams of corresponding wavelengths incident on the sub-grating portions 2621 of different levels are also different.

[0204] For example, the 0th-order sub-grating portion is configured to receive a laser beam having a first wavelength, and the laser beam having the first wavelength undergoes 0th-order diffraction on the 0th-order sub-grating portion. For example, the optical power of the laser beam having the first wavelength accounts for 20% to 50% of the optical power of the laser beam emitted by the laser chip 201.

[0205] For example, the first-order sub-grating portion is configured to receive a laser beam having a second wavelength, and the laser beam having the second wavelength undergoes first-order diffraction at the first-order sub-grating portion. For example, the optical power of the laser beam having the second wavelength accounts for 50% to 80% of the optical power of the laser beam emitted by the laser chip 201.

[0206] It is understandable that in order to achieve the diffraction effect, it is necessary to make the laser beam with the second wavelength that accounts for most of the optical power among the laser beams of different wavelengths emitted by the laser chip 201, so that the first-order diffraction occurs at the first-order sub-grating portion.

[0207] When the laser beam passes through the grating portion 262, the structure of the sub-grating portion 2621, the incident angle of the laser beam, and the diffraction angle of the reflective diffraction grating 260 can satisfy the formula (2), that is, d(sinθ α +sinθ i )=nλ; Formula (2)

[0208] In formula (2), d is the period of the sub-grating portion 2621, θ α is the incident angle of the laser beam, θ i is the diffraction angle of the reflective diffraction grating 260 , n is the diffraction order of the sub-grating portion 2621 , n=±1, ±2, ±3, etc., and λ is the wavelength of the laser beam after passing through the sub-grating portion 2621 .

[0209] It can be understood that, according to formula (2), when the incident angle of the laser beam incident on the reflective diffraction grating 260 is equal to the diffraction angle of the reflective diffraction grating 260, the efficiency of the first-order diffraction of the laser beam on the first-order sub-grating portion is the highest, that is, θ α =θ i .

[0210] According to formula (2), the grating formula is: 2d sin θ littrow =λ; Formula (3)

[0211] In formula (3), θ littrow is the Littrow configuration angle.

[0212] The incident angle of the laser beam after being collimated by the collimating lens 250 relative to the reflective diffraction grating 260 is a constant value, that is, the incident angle θ relative to the reflective diffraction grating 260 is α Therefore, when the diffraction order of the reflective diffraction grating 260 is 1 (ie, n=1), the Littrow configuration angle θ is littrow is equal to the blaze angle of the reflective diffraction grating 260. The blaze angle is the angle between the grating reflective surface and the surface of the sub-grating portion 2621. The grating reflective surface is the working surface of the reflective diffraction grating 260, and is also the angle between the normal line of the reflective surface and the normal line of the grating plane.

[0213] Therefore, the tuning wavelength λ of the reflective diffraction grating 260 is only related to the period d of the sub-grating portion 2621. Therefore, in order to achieve the purpose of changing the wavelength λ, the period d of each sub-grating portion 2621 can be changed.

[0214] In some embodiments, a reflective diffraction grating 260 can be formed by depositing a metal film on an optical element and carving a plurality of parallel grooves in the metal film to form a plurality of sub-grating sections 2621. For example, materials such as diamond, prisms, or glass can be deposited on the optical element. For example, laser micromachining or photolithography techniques can be used to carve a plurality of sub-grating sections 2621 in the metal film, thereby obtaining a plurality of sub-grating sections 2621 with a smaller pitch.

[0215] In some embodiments, the reflective diffraction grating 260 may be a metal grating having a metal reflective surface with high reflectivity configured to reflect the laser beam. For example, the reflective diffraction grating 260 may be made of a metal material such as gold, silver, or aluminum.

[0216] According to formula (3), the period d of the sub-grating portion 2621 of the reflective diffraction grating 260 corresponds to the wavelength of the laser beam of the laser chip 201. Therefore, in some embodiments, the red laser chip assembly 210 further includes a first reflective grating portion adapted to the red laser chip. The period of the first reflective grating portion is adapted to the wavelength of the red laser. The green laser chip assembly 220 further includes a second reflective grating portion adapted to the green laser chip. The period of the second reflective grating portion is adapted to the wavelength of the green laser. The blue laser chip assembly 230 includes a third reflective grating portion adapted to the blue laser chip. The period of the third reflective grating portion is adapted to the wavelength of the blue laser.

[0217] In some embodiments, the laser 1 further includes a cover plate 14, which is disposed on the housing 100 and blocks the light outlet of the housing 100 to seal the accommodating cavity 13. The cover plate 14 is made of a transparent material. For example, the cover plate 14 can be made of sealing glass, sapphire, quartz, or other materials.

[0218] In some embodiments, a semi-reflective film is provided on the side of the cover plate 14 facing the accommodating cavity 13, and an anti-reflective film is provided on the side of the cover plate 14 facing away from the accommodating cavity 13. It is understood that the laser beam diffracted by the reflective diffraction grating 260 will pass through the cover plate 14 and be emitted from the light outlet. This arrangement allows the laser beam to return along its original path and form an external resonant cavity with the rear cavity surface of the laser chip 201. Ultimately, the central wavelengths of the laser beams emitted from the cover plate 14 are all different.

[0219] Figure 23 is a wavelength distribution diagram of a laser chip assembly after wavelength tuning according to some embodiments. As shown in Figure 23, the laser 1 can achieve the purpose of wavelength tuning and speckle suppression.

[0220] In some embodiments, the reflectivity of cover plate 14 is less than 5%, which does not affect the output power of laser 1 while still enabling oscillation of the external resonant cavity. The laser beam partially reflected by cover plate 14 forms a resonant cavity with laser chip 201, and wavelength tuning is achieved through laser oscillation in the resonant cavity.

[0221] 24 is a cross-sectional view of yet another laser according to some embodiments.

[0222] In some embodiments, as shown in FIG24 , the laser 1 further includes a light homogenizer 15 , which is disposed on a side of the cover plate 14 away from the accommodating cavity 13 and is configured to uniformly distribute the laser beam emitted from the cover plate 14 . For example, the light homogenizer 15 may be a fly-eye lens or a light pipe. The fly-eye lens can homogenize the laser beam. Furthermore, the area of ​​the light-entering surface of the light pipe is smaller than the area of ​​the emitting end. A laser beam with a larger beam angle, after reflection in the light pipe, has a smaller beam angle of the outgoing light, thereby achieving homogenization and collimation of the laser beam and eliminating speckle.

[0223] In some embodiments, as shown in FIG24 , the laser 1 further includes a diffuser 16. The diffuser 16 is disposed on a side of the cover plate 14 away from the accommodating cavity 13 and is configured to diffuse and homogenize the laser beam emitted from the cover plate 14, thereby evenly diffusing the three-color laser beams and eliminating speckles.

[0224] Those skilled in the art will understand that the scope of the present invention is not limited to the above specific embodiments, and that certain elements of the embodiments may be modified and replaced without departing from the spirit of the present application. The scope of the present application is limited by the appended claims.

Claims

1. A laser comprising: The housing comprises: Base plate; and A side wall is provided on the bottom plate; A plurality of laser chip assemblies are arranged on the base plate; and A shaping and homogenizing component is connected to the side wall and is located on a side of the side wall away from the bottom plate; the shaping and homogenizing component and the shell together define a first enclosed space; the multiple laser chip assemblies are located in the first enclosed space; the shaping and homogenizing component is located on the output light path of the laser chip assembly and is configured to receive the laser beam emitted by the laser chip assembly and collimate and diffract and homogenize the received laser beam.

2. The laser according to claim 1, wherein The shaping and homogenizing component comprises: a plurality of first collimating sections, arranged corresponding to the plurality of laser chip assemblies; the first collimating sections are configured to receive and collimate the laser beams emitted by the corresponding laser chip assemblies; and a diffraction portion located on a side of the plurality of first collimating portions away from the plurality of laser chip assemblies and configured to diffract and homogenize the laser beam passing through the diffraction portion; the diffraction portion comprising a plurality of diffraction structures; the diffraction structures being distributed in two dimensions; The laser beam emitted by the laser chip assembly is collimated by the corresponding first collimating portion and then diffracted and homogenized by the diffraction portion.

3. The laser according to claim 2, wherein The diffraction structure includes at least one of a sawtooth structure, a trapezoidal structure, an inclined rectangular structure or a stepped structure.

4. The laser according to claim 2, further comprising a plurality of plane mirrors, wherein the plurality of plane mirrors are located in the housing; any one of the plurality of plane mirrors corresponds to at least one laser chip assembly among the plurality of laser chip assemblies and is located on the light-emitting side of the corresponding at least one laser chip assembly; the plane mirror is configured to receive at least one laser beam emitted by the corresponding at least one laser chip assembly and reflect the at least one laser beam into at least one first collimation portion among the corresponding plurality of first collimation portions.

5. The laser according to claim 4, wherein The shaping and homogenizing component further includes a substrate, which is located on a side of the sidewall facing away from the bottom plate and defines the first enclosed space together with the housing; the plurality of first collimating portions are provided on a surface of the substrate facing the laser chip assembly, and the diffraction portion is provided on a surface of the substrate facing away from the laser chip assembly; Wherein, the first collimating portion is a convex lens or a Fresnel lens protruding toward the laser chip assembly.

6. The laser according to claim 4, wherein The shaping and homogenizing component also includes: a first substrate, located on a side of the side wall facing away from the bottom plate, and defining the first enclosed space together with the housing; a second substrate, located on a side of the first substrate facing away from the housing; Wherein, the shaping and homogenizing component satisfies one of the following conditions: The first substrate and the second substrate are bonded together; the plurality of first collimating portions are arranged on a surface of the first substrate facing the laser chip assembly, and the diffraction portion is arranged on a surface of the second substrate away from the laser chip assembly; as well as, The first substrate and the second substrate are spaced apart from each other by a predetermined distance in a direction perpendicular to the bottom plate; the plurality of first collimating portions are located on a surface of the first substrate facing the laser chip assembly; the shaping and homogenizing component includes at least one diffraction portion, and the at least one diffraction portion is disposed on at least one surface of the second substrate; Wherein, the first collimating portion is a convex lens or a Fresnel lens protruding toward one side of the laser chip assembly.

7. The laser according to claim 2, further comprising: A plurality of curved reflectors are located in the housing and correspond to the plurality of laser chip assemblies; the curved reflectors are located on the light-emitting side of the corresponding laser chip assemblies; a surface of the curved reflector facing the corresponding laser chip assembly is configured as a concave curved surface; the curved reflector is configured to receive the laser beam emitted by the corresponding laser chip assembly, collimate the received laser beam, and reflect the collimated laser beam to the diffraction portion; The shaping and homogenizing component further includes a base plate, which is located on a side of the side wall away from the bottom plate and defines the first closed space together with the shell; Wherein, the diffraction portion satisfies one of the following: The diffraction portion is located on the surface of the substrate facing away from the curved reflector; as well as; The diffraction portion is located on a surface of the substrate facing the curved reflector.

8. The laser according to claim 7, wherein The shaping and homogenizing component further includes a plurality of second collimating portions; the plurality of second collimating portions are arranged corresponding to the plurality of laser chip assemblies; the second collimating portions are configured to receive and collimate the laser beams emitted by the corresponding laser chip assemblies; Wherein, the shaping and homogenizing component satisfies one of the following conditions: The diffraction portion is located on a surface of the substrate facing away from the curved reflector, and the plurality of second collimating portions are located on a surface of the substrate facing the curved reflector; as well as, The diffraction portion is located on a surface of the substrate facing the curved reflector, and the plurality of second collimating portions are located on a surface of the substrate facing away from the curved reflector.

9. The laser according to any one of claims 1 to 8, further comprising: a supporting portion, disposed on the inner wall of the side wall and extending along the circumference of the side wall; Sealing glass is connected to the support portion and blocks the support portion; the bottom plate, a portion of the side wall, the support portion and the sealing glass together define a second closed space; Wherein, the sealing glass and the supporting part are fixed by welding; and the shaping and homogenizing component and the shell are fixed by adhesive.

10. The laser according to any one of claims 1 to 9, wherein The laser chip assembly comprises: a laser chip configured to emit a laser beam; and a reflective diffraction grating disposed on the light-emitting side of the laser chip; the period of the reflective diffraction grating being adapted to the wavelength of the laser beam emitted by the laser chip; the reflective diffraction grating being configured to reflect the laser beam and adjust the central wavelength of the laser beam; The multiple laser beams emitted by the multiple laser chips in the multiple laser chip assemblies have different central wavelengths after being reflected by the multiple reflective diffraction gratings in the multiple laser chip assemblies.

11. The laser according to claim 10, wherein The incident angle of the laser beam when incident on the reflective diffraction grating is equal to the diffraction angle of the reflective diffraction grating.

12. The laser according to claim 10 or 11, wherein The reflective diffraction grating is a metal grating, which includes a metal reflective surface and is configured to reflect the laser beam.

13. The laser according to any one of claims 10 to 12, wherein The reflective diffraction grating comprises: a first reflecting mirror, tiltedly disposed on the bottom plate; and The grating portion is provided on a surface of the first reflector facing the laser chip and is configured to change at least one of a phase or a center wavelength of the laser beam incident on the grating portion.

14. The laser according to any one of claims 10 to 12, wherein The reflective diffraction grating comprises: a right-angle reflecting prism, the bottom surface of which is fixedly connected to the bottom plate; and The grating portion is provided on a surface of the right-angle reflection prism facing the laser chip and is configured to change at least one of a phase or a center wavelength of the laser beam incident on the grating portion.

15. The laser according to any one of claims 10 to 14, wherein The laser chip assembly further includes a collimating lens, which is disposed between the laser chip and the reflective diffraction grating and configured to collimate the laser beam and transmit the collimated laser beam to the reflective diffraction grating.

16. The laser according to any one of claims 10 to 15, wherein The plurality of laser chip assemblies include: At least one red laser chip assembly arranged in at least one row; the red laser chip assembly comprises: A red laser chip configured to emit red laser light; and a first reflective grating adapted to the red laser chip; At least one green laser chip assembly arranged in at least one row; the green laser chip assembly comprises: a green laser chip configured to emit green laser light; and a second reflective grating adapted to the green laser chip; and At least one blue laser chip assembly arranged in at least one row; the blue laser chip assembly comprises: a blue laser chip configured to emit blue laser light; and The third reflective grating is adapted to the blue laser chip.

17. The laser according to any one of claims 10 to 16, wherein The housing defines an accommodating cavity; a side of the side wall away from the bottom plate is open to form a light outlet, and the bottom plate is arranged opposite to the light outlet; The laser also includes a cover plate, which is sealed at the light outlet to seal the accommodating cavity; a semi-reflective film is provided on the side of the cover plate facing the accommodating cavity, and an anti-reflective film is provided on the side of the cover plate facing away from the accommodating cavity. 18 . The laser according to claim 17 , further comprising a light homogenizer, wherein the light homogenizer is disposed on a side of the cover plate away from the accommodating cavity and is configured to uniformly distribute the laser beam emitted from the cover plate.

19. A laser projection system, comprising at least one laser according to any one of claims 1 to 18, a light modulation component located on the light output side of the laser, and a projection lens located on the light output side of the light modulation component. 20 . The projection system according to claim 19 , further comprising an illumination lens group, wherein the illumination lens group is located between the at least one laser and the light modulation component and is configured to shape and homogenize the laser beam emitted by the at least one laser.

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