Uniform laser light source

Abstract

The embodiment of the invention discloses a uniform laser, which is used for obtaining a circular light spot with uniformly distributed light intensity, and comprises a laser chip used for emitting an initial light beam; the collimation assembly is used for processing the initial light beam to obtain a collimated light beam; the homogenizing assembly comprises a first absorption unit and a reflection unit, the first absorption unit is used for absorbing light in a circular area in the middle of the collimated light beam, and the reflection unit is used for reflecting light in an annular area except the circular area in the collimated light beam to the first absorption unit; and the collimated light beam is guided to an extension area in the emergent direction of the collimated light beam along the circular area to form uniform laser, and the light intensity distribution in the annular area of the collimated light beam is uniform.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical technology, and in particular, to a uniform laser light source. Background Art

[0002] Laser light sources have the advantages of good monochromaticity, strong directionality, high brightness, long life and small size, and are widely used in industry, agriculture, medicine, scientific research and other fields. Laser beam quality is an important technical indicator of laser light sources, which directly affects the application effect of laser light sources. For example, when analyzing the accuracy of laser ranging and laser height measurement, the laser beam quality has a significant impact on the ranging echo, so ranging beam quality detection is an important link.

[0003] There are many factors that affect the quality of the beam. For example, when the vertical-cavity surface-emitting laser (VCSEL) is operating at a relatively high drive current, the light spot output by the VCSEL presents a circular distribution with a dark center and bright edges. As a laser light source, this circular light intensity distribution is not suitable in most application scenarios. It is necessary to add high-quality optical elements or optical devices to adjust the light intensity distribution of the beam in order to obtain a circular light spot with uniform light intensity distribution. Summary of the invention

[0004] The embodiment of the present application provides a uniform laser for obtaining a circular light spot with uniform light intensity distribution.

[0005] A first aspect of an embodiment of the present application provides a uniform laser, comprising:

[0006] A laser chip, used to emit the initial light beam;

[0007] A collimating component, used for processing the initial light beam to obtain a collimated light beam;

[0008] A homogenization component includes a first absorption unit and a reflection unit, wherein the first absorption unit is used to absorb light in a circular area in the middle of the collimated light beam, and the reflection unit is used to guide light in an annular area other than the circular area in the collimated light beam to an extension area along the circular area in the exit direction of the collimated light beam to form a uniform laser, and the light intensity distribution in the annular area of ​​the collimated light beam is uniform.

[0009] In some specific implementations, the reflecting unit includes a first reflecting mirror and a second reflecting mirror, the reflecting surface of the first reflecting mirror is a truncated cone surface, the reflecting surface of the second reflecting mirror is a conical surface or a truncated cone surface, the diameter of the bottom circle of the second reflecting mirror is not greater than the diameter of the first absorbing unit, the reflecting surface of the first reflecting mirror and the reflecting surface of the second reflecting mirror have the same generatrix inclination angle, and the optical axis of the first absorbing unit, the symmetry axis of the first reflecting mirror, the symmetry axis of the second reflecting mirror, and the optical axis of the collimated light beam coincide;

[0010] The light in the annular area is reflected by the reflection surface of the first reflector to the reflection surface of the second reflector, and the reflection surface of the second reflector is used to reflect the light in the annular area to an extension area along the circular area in the direction of the collimated light beam emission to form the uniform laser.

[0011] In some specific implementations, the reflecting unit includes a first reflecting mirror and a second reflecting mirror, the reflecting surface of the first reflecting mirror is a truncated cone surface, the reflecting surface of the second reflecting mirror is a conical surface or a truncated cone surface, the diameter of the bottom circle of the second reflecting mirror is not greater than the diameter of the first absorbing unit, the reflecting surface of the first reflecting mirror and the reflecting surface of the second reflecting mirror have the same generatrix inclination angle, the annular region includes an inner ring region and an outer ring region having the same center, and the optical axis of the first absorbing unit, the symmetry axis of the first reflecting mirror, the symmetry axis of the second reflecting mirror, and the optical axis of the collimated light beam coincide;

[0012] The light in the outer ring area is reflected by the reflecting surface of the first reflector to the reflecting surface of the second reflector. The reflecting surface of the second reflector is used to reflect the light in the outer ring area to the extension area along the circular area in the exit direction of the collimated light beam. The light in the extension area and the light in the inner ring area form the uniform laser.

[0013] In some specific implementations, the homogenization assembly further includes a second absorption unit, and the outer surface of the second absorption unit is used to absorb stray light;

[0014] The top surface diameter of the second absorption unit is the same as the diameter of the bottom surface circle of the second reflector, and the top surface of the second absorption unit is in contact with the bottom surface circle of the second reflector. The first end surface of the first absorption unit is a circle with the same diameter as the bottom surface of the second absorption unit, and the first end surface of the first absorption unit is in contact with the bottom surface of the second absorption unit.

[0015] In some specific implementations, the outer surface of the second absorption unit, the second end face of the first absorption unit away from the first end face, and the side of the first absorption unit are coated with black paint, and the black paint is used to absorb light in a target band, where the target band is the band where the initial light beam is located.

[0016] In some specific implementations, the bonding is a fixed connection or a detachable connection.

[0017] In some specific implementations, the incident angle of the collimated light beam incident on the first reflector is greater than the corresponding total reflection angle, and the light incident on the second reflector has an incident angle greater than the corresponding total reflection angle.

[0018] In some specific implementations, the laser chip is electrically connected to a substrate;

[0019] The uniform laser light source further includes: a mounting bracket, the substrate is fitted to one end of the mounting bracket, and the collimating assembly, the first reflector and the second reflector are arranged on the mounting bracket along the emitting direction of the collimated light beam.

[0020] In some specific implementations, the mounting bracket includes a first bracket and a second bracket.

[0021] The collimation assembly is arranged in the first bracket, and two ends of the first bracket are respectively attached to the substrate and the second bracket;

[0022] The collimating assembly is arranged on the second bracket.

[0023] In some specific implementations, the first bracket and the collimation assembly are manufactured in one piece through an injection molding process or a hole digging process.

[0024] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages: the light spot emitted by the VCSEL in the prior art of the present application is presented as a darker circular area and a brighter annular area with the same center as the aforementioned circular area, and the embodiments of the present application analyze the light intensity distribution at various places of the light spot and find that the light beam in the aforementioned annular area is evenly distributed. Therefore, the embodiments of the present application utilize the principle of geometric optics, select the reflection unit to guide the light in the annular area in the collimated light beam to the extension area along the circular area in the direction of the collimated light beam, and select the first absorption unit to absorb the light in the circular area in the middle of the collimated light beam, so as to achieve the absorption and recombination of the light beam, and make the light intensity distribution uniform at various places in the finally obtained uniform laser. The embodiments of the present application obtain uniform laser at a relatively low cost, which can be applied to various forms of laser light sources such as point laser light sources and surface laser light sources. Moreover, the uniform laser of the present application has a compact structure and a simple homogenization principle, which has great advantages in material cost and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0026] Figure 1 A schematic diagram of the structure of a uniform laser according to an embodiment of the present application;

[0027] Figure 2 Another schematic diagram of the structure of the uniform laser according to the embodiment of the present application;

[0028] Figure 3 This is a schematic diagram of the effect of the homogenization principle of the embodiment of the present application;

[0029] Figure 4 Another schematic diagram of the structure of the uniform laser according to the embodiment of the present application;

[0030] Figure 5 Another schematic diagram of the structure of the uniform laser according to the embodiment of the present application;

[0031] Wherein, the accompanying drawings are marked as follows:

[0032] 1. Laser chip; 2. Collimation assembly; 3. Homogenization assembly; 31. First absorption unit; 32. Reflection unit; 321. First reflector; 322. Second reflector; 33. Second absorption unit; 4. Substrate; 41. Laser base; 42. Electrical connection; 5. Mounting bracket; 51. First bracket; 52. Second bracket; 53. Third bracket; 6. Light outlet. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0035] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0036] See also Figure 1 , the present application provides a uniform laser light source, comprising:

[0037] Laser chip 1, used for emitting an initial light beam;

[0038] A collimating component 2, used for processing an initial light beam to obtain a collimated light beam;

[0039] The homogenization component 3 includes a first absorption unit 31 and a reflection unit 32. The first absorption unit 31 is used to absorb the light in the circular area in the middle of the collimated light beam. The reflection unit 32 is used to guide the light in the annular area other than the circular area in the collimated light beam to the extension area along the circular area in the emitting direction of the collimated light beam to form a uniform laser. The light intensity distribution in the annular area of ​​the collimated light beam is uniform.

[0040] In order to better illustrate the technical solution of the embodiment of the present application, the inventive concept of the uniform laser light source of the present application is firstly explained.

[0041] As mentioned in the background technology, when VCSEL works under a large driving current, it will excite high-mode to form a multi-mode laser light source. One of the most common manifestations is that the output light spot presents a circular distribution with a dark center and bright edges. Among them, except for the dark part in the center, the brightness of the circular ring outside the light spot is uniform. Therefore, the inventor of this application creatively thought of regulating the propagation of the light beam to filter out the light in the dark area in the center and reorganize the uniform light on the outside, and finally obtain a circular light spot with uniform energy distribution at the output interface.

[0042] It is understandable that the light beam emitted by the laser chip 1 has a certain divergence angle, which cannot meet the actual use requirements. Therefore, the laser chip 1 is generally processed by the collimating component 2 before the laser chip 1 reaches the surface of the object. In actual application, the present application found that the spot of the collimated initial light beam (i.e., the collimated light beam) under certain working current conditions is a circular ring distribution with a dark center and bright edges. On this basis, the present application embodiment introduces a homogenizing component 3. The homogenizing component 3 of the embodiment of the present application includes a first absorption unit 31 and a reflection unit 32 according to the aforementioned inventive concept. Among them, the first absorption unit 31 is used to absorb the light in the circular area in the middle of the collimated light beam, or the light in the dark area in the middle of the collimated light beam. Specifically, the first absorption unit 31 can absorb light including the light in the circular area centered on the optical axis of the collimated light beam, and the radius of the circular area can be set as needed and is not limited here; the reflection unit 32 is used to guide the light in the annular area other than the circular area in the collimated light beam to the extension area along the circular area in the exit direction of the collimated light beam to form a uniform laser. It should be noted that since the light in the annular area in the collimated light beam is collimated and evenly distributed, the embodiment of the present application only needs to guide the light in the annular area to the circular area centered on the optical axis of the collimated light beam for uniform distribution through the reflection principle.

[0043] It can be seen that the homogenization component 3 of the embodiment of the present application is completely different from the high-cost diffractive optical element (DOE). The embodiment of the present application utilizes the principle of geometric optics, selects the reflection unit 32 to guide the light in the annular area in the collimated light beam to the extension area along the circular area in the exit direction of the collimated light beam, and selects the first absorption unit 31 to absorb the light in the circular area in the middle of the collimated light beam, thereby achieving the absorption and recombination of the light beam, and making the light intensity distribution uniform at all locations in the finally obtained uniform laser. The embodiment of the present application obtains uniform laser at a relatively low cost, and can be applied to various forms of laser light sources such as point laser light sources and surface laser light sources. Moreover, the uniform laser of the present application has a compact structure and a simple homogenization principle, which has great advantages in material cost and production efficiency.

[0044] For some specific implementations, see Figure 2The reflecting unit 32 of the embodiment of the present application may specifically include: a first reflecting mirror 321 and a second reflecting mirror 322, the reflecting surface of the first reflecting mirror 321 is a truncated cone surface, the reflecting surface of the second reflecting mirror 322 is a conical surface or a truncated cone surface, the reflecting surface of the first reflecting mirror 321 and the reflecting surface of the second reflecting mirror 322 have the same generatrix inclination angle, the optical axis of the first absorption unit 31, the symmetry axis of the first reflecting mirror 321, the symmetry axis of the second reflecting mirror 322 and the optical axis of the collimated light beam coincide; the light in the annular area is reflected from the reflecting surface of the first reflecting mirror 321 to the reflecting surface of the second reflecting mirror 322, and the reflecting surface of the second reflecting mirror 322 is used to reflect the light in the annular area to an extension area along the circular area in the exit direction of the collimated light beam to form a uniform laser.

[0045] First, in order to better perform similar steering processing on light parallel to the optical axis of the collimated light beam at different positions in space, that is, light incident on the reflector in parallel remains parallel after being emitted, the reflective surface of the first reflector 321 of the embodiment of the present application is set to a truncated cone surface, and the reflective surface of the second reflector 322 is a conical surface or a truncated cone surface.

[0046] Secondly, in order to make the emission direction of the collimated light beam consistent with the emission direction of the uniform laser, the embodiment of the present application also sets the same generatrix inclination angle for the reflection surface of the first reflector 321 and the reflection surface of the second reflector 322. It can be understood that when a beam of light is incident on two parallel reflectors, the angle at which the beam is emitted from the second incident reflector should be the same as the angle at which it is incident from the first incident reflector.

[0047] Furthermore, in order to ensure that the optical axis of the uniform laser coincides with the optical axis of the collimated light beam, the embodiment of the present application also needs to ensure that the optical axes of the optical components in the embodiment of the present application are in the same position. In other words, the optical axis of the first absorption unit 31, the symmetry axis of the first reflector 321, the symmetry axis of the second reflector 322, and the optical axis of the collimated light beam coincide. Specifically, the optical axis coincidence can be achieved by precision fixture positioning, machine vision positioning, or optical joint coupling.

[0048] Finally, the light in the annular area is reflected by the reflection surface of the first reflection mirror 321 to the reflection surface of the second reflection mirror 322, and the reflection surface of the second reflection mirror 322 is used to reflect the light in the annular area to the extension area along the circular area in the direction of the collimated light beam to form uniform laser.

[0049] It should be noted that, in order to ensure that the light beam processed by the reflection unit 32 is uniform, the embodiment of the present application needs to control the size of the first absorption unit 31, as well as the generatrix inclination angle of the reflection surfaces of the first reflector 321 and the second reflector 322, so as to adjust the diameter of the circular area and the width of the annular area in the collimated light beam, so that the light beam emitted from the homogenization component 3 forms a uniform laser in the extension area of ​​the collimated light beam emission direction. Specifically, the reflection surface of the first reflector 321 should have a generatrix inclination angle of forty-five degrees, and the reflection surface of the second reflector 322 should also have a generatrix inclination angle of forty-five degrees, and the diameter of the first absorption unit 31 is equal to the radius of the collimated light beam. Among them, the generatrix inclination angle refers to the angle between the generatrix and the vertical plane, and the vertical plane is perpendicular to the bottom surface of the reflection surface.

[0050] In other implementations, see Figure 3 The reflecting unit 32 of the embodiment of the present application is similar to the reflecting unit 32 in the aforementioned embodiment, with the difference that the annular area includes an inner annular area and an outer annular area with the same center, and the light in the outer annular area is reflected by the reflecting surface of the first reflecting mirror 321 to the reflecting surface of the second reflecting mirror 322, and the reflecting surface of the second reflecting mirror 322 is used to reflect the light in the outer annular area to an extended area along the circular area in the direction of the collimated light beam emission, and the light in the extended area and the light in the inner annular area form a uniform laser.

[0051] That is, the difference between the embodiment of the present application and the above embodiment mainly lies in whether all the light in the annular area is processed by the reflection unit 32 to form a part of the uniform laser. In practical applications, this setting can be selected as needed based on factors such as the diameter of the required uniform laser, and is not limited here.

[0052] In the above-mentioned embodiment, all the light in the annular area will be processed by the reflection unit 32 to form a part of the uniform laser, while in the embodiment of the present application, the annular area is divided into an inner ring area and an outer ring area with the same center, and only the light in the outer ring area will pass through the reflection surface of the first reflector 321 and the reflection surface of the second reflector 322, and the light in the inner ring area will be directly emitted from the uniform laser light source, and together with the light emitted from the second reflector 322, form a uniform laser. For details, please refer to Figure 3 Schematic diagram of the homogenization principle is shown.

[0053] It should also be noted that in order to ensure that the light beam processed by the reflection unit 32 is uniform, the embodiment of the present application needs to control the generatrix inclination angles of the reflection surfaces of the first reflection mirror 321 and the second reflection mirror 322, and adjust the ring width of the inner ring area and the outer ring area in the annular area processed by the reflection surface of the first reflection mirror 321, so that the light beam emitted from the homogenization component 3 forms a uniform laser in the extension area of ​​the collimated light beam emission direction. Specifically, the reflection surface of the first reflection mirror 321 should have a generatrix inclination angle of forty-five degrees, and the reflection surface of the second reflection mirror 322 should also have a generatrix inclination angle of forty-five degrees, and the radius of the first absorption unit 31 is equal to the ring width of the outer ring area.

[0054] In the foregoing, various implementations are described in which the reflection surface of the first reflector 321 of the embodiment of the present application is a conical surface and the second reflector 322 is a conical surface or a truncated cone surface. In another implementation, the reflection surface of the first reflector 321 of the embodiment of the present application can also be a first free-form surface and the reflection surface of the second reflector 322 can also be a second free-form surface, or one of the reflection surfaces corresponding to the first reflector 321 and the second reflector 322 is a free-form surface and the other is a conical surface or a truncated cone surface. Specifically, if the reflection surface of any reflector is a free-form surface, the surface shape of the free-form surface can be obtained by simulation design using optical simulation software such as Zemax, Code V or COMSOL, and is not specifically limited here.

[0055] Further, on the basis of the above-mentioned embodiment, in order to avoid the light in the collimated light beam being incident on the inner surface of the second reflector 322 and refracted to form stray light, which affects the final imaging effect, the maximum diameter of the cross section of the second reflector 322 in the embodiment of the present application is not greater than the diameter of the first absorption unit 31. It should be noted that the points where any plane perpendicular to the optical axis of the second reflector 322 intersects with the reflective surface of the second reflector 322 constitute the cross section of the second reflector 322. Since the reflective surface of the second reflector 322 can be a truncated cone surface or a conical surface, the maximum diameter of the cross section of the second reflector 322 should be the end face diameter of the truncated cone enclosed by the reflective surface of the second reflector 322, which is larger than the diameter of the end face or the bottom circle diameter of the cone.

[0056] Based on the above embodiment, in a specific implementation, the homogenization component 3 further includes: Figure 4 The second absorption unit 33 shown in the figure has an outer surface used to absorb stray light generated in the entire optical system. At the same time, in order to avoid generating additional stray light, the embodiment of the present application hopes that the two ends of the second absorption unit 33 are closely attached to the bottom surface of the first reflector 321 of the same size and the first end surface of the first absorption unit 31 of the same size. Figure 4In other words, the top diameter of the second absorption unit 33 is the same as the bottom diameter of the second reflector 322, the top surface of the second absorption unit 33 fits the bottom surface of the second reflector 322, the first end surface of the first absorption unit 31 is a circle with the same diameter as the bottom surface of the second absorption unit 33, and the first end surface of the first absorption unit 31 fits the bottom surface of the second absorption unit 33. The fitting is any connection method that can meet the requirements of the required optical device, such as fixed connection (such as fixed by adhesive bonding) or detachable connection.

[0057] In practical applications, the outer surface of the second absorption unit 33, the second end face of the first absorption unit 31 away from the first end face, and the side of the first absorption unit 31 are coated with black paint, and the black paint is used to absorb light in the target band, which is the band where the initial light beam is located.

[0058] For other specific implementations, please continue to refer to Figure 4 In order to make the entire uniform laser constitute a convenient module, the laser chip 1 can be electrically connected 42 to the substrate 4; at the same time, the uniform laser light source also includes: a mounting bracket 5, the substrate 4 is fitted with one end of the mounting bracket 5, and the collimating component 2, the first reflector 321 and the second reflector 322 are arranged on the mounting bracket 5 along the emission direction of the collimated light beam.

[0059] The mounting bracket 5 of the embodiment of the present application is a sleeve with a certain wall thickness, the cross section of the inner surface of the sleeve in the direction perpendicular to the optical axis (of the initial light beam) is a circle with the same size as the lens aperture, and the cross section of the outer surface of the sleeve in the direction perpendicular to the optical axis (of the initial light beam) can be designed and customized according to actual needs, and the length of the sleeve can also be designed and customized according to actual needs and the parameters of the collimator assembly 2. Since the substrate 4 is attached to one end of the mounting bracket 5, and the laser chip 1 is electrically connected 42 to the substrate 4, the distance between the collimator assembly 2 and the substrate 4 is preferably approximately equal to the focal length of the collimator assembly 2.

[0060] Furthermore, the mounting bracket 5 includes a first bracket 51 and a second bracket 52, the collimating assembly 2 is arranged in the first bracket 51, and the two ends of the first bracket 51 are respectively attached to the substrate 4 and the second bracket 52; the collimating assembly 2 is arranged on the second bracket 52. Figure 5 It can be seen from the structure shown that if the collimating assembly 2 is disposed in the first bracket 51, the collimating assembly 2 and the first bracket 51 can be integrally formed by an integral injection molding process or a hole digging process.

[0061] Furthermore, the embodiments of the present application may also include: Figure 5The light outlet 6 shown is designed based on the difficulty of processing and the stability of use of the homogenizing component 3, and its thickness can be customized according to actual needs; the third bracket 53 is respectively fitted with the third bracket 53 (or the mounting bracket 5) and the first reflector 321 in a manner similar to the aforementioned related embodiments.

[0062] Finally, it should be noted that in order to reduce the energy loss of the entire light beam, the incident angle of the collimated light beam incident on the first reflector 321 is greater than the corresponding total reflection angle, and the light incident on the second reflector 322 has an incident angle greater than the corresponding total reflection angle. The reflection angle is calculated based on the refractive index of the first reflector 321, the refractive index of the second reflector 322, and the refractive index of air.

[0063] In some specific implementations, the laser chip 1 of the embodiment of the present application can be a chip designed mainly based on VCSEL. The laser chip 1 can be electrically connected 42 to the laser base 41 by means of planar solid crystal or eutectic, and the number of chips and the position of chip solid crystal can be adjusted on the plane as needed. Specifically, the surface of the substrate 4 contains a laser base 41 (and a pad), which can be used to fix the chip in a plane (and weld), and the substrate 4 contains a copper circuit inside; the electrical connection 42 between the laser chip 1 and the laser base 41 is a gold wire or a copper wire, which can connect the copper circuit inside the substrate 4 to realize the electrical connection 42 between the laser light source and the outside. Among them, the substrate 4 can be a PCB board made of plastic, ceramic or metal. The collimation component 2, sleeve, and homogenization component 3 of the embodiment of the present application can be any material such as plastic or glass that can realize the corresponding function.

[0064] The uniform laser of the embodiment of the present application is described below in a specific embodiment.

[0065] The present embodiment provides a uniform laser, comprising a laser chip 1, a substrate 4, a collimator assembly 2, and a homogenizer assembly 3. The laser chip 1 is die-bonded on a laser base 41 of the substrate 4, the light emitting center of the laser chip 1, the optical axis of the collimator assembly 2, and the center axis of the homogenizer assembly 3 are positioned to substantially coincide, and then the substrate 4, the collimator assembly 2, and the homogenizer assembly 3 are bonded and fixed together in sequence using an adhesive.

[0066] The laser chip 1 is a VCSEL, which is fixed on the laser base 41 of the substrate 4 by means of a planar die-bonding method through an adhesive; the collimating component 2 is a lens, the convex lens and the mounting bracket 5 are integrally molded by injection, the optical axis of the convex lens coincides with the central axis of the mounting bracket 5, and the upper and lower end surfaces of the first bracket 51 can be coated with adhesive to be bonded and fixed to the substrate 4 and the first absorption unit 31 respectively. The length of one end of the first bracket 51 fixed to the substrate 4 is approximately equal to the focal length f of the lens.

[0067] The homogenization component 3 includes two optical functional components: a first absorption unit 31, a second absorption unit 33 and a reflection unit 32. The first absorption unit 31 is a disk with a black coating on the outer surface, which is used to absorb light; the second absorption unit 33 is a truncated cone surface, a cylindrical surface, a cylinder or a truncated cone with a black coating on the outer surface, which is used to absorb stray light; the first absorption unit 31 and the second bracket 52 can be integrally injection molded, and a transparent circular platform that can carry the first absorption unit 31 is provided in the second bracket 52. The upper and lower end surfaces of the edge of the second bracket 52 can be coated with adhesive to be bonded and fixed to the collimation component 2 and the first reflection unit 32 respectively. The second absorption unit 33 of the reflection unit 32 is designed as a truncated cone surface, and the outer wall of the central cylindrical hole is coated with black coating to absorb light. The first reflection component is parallel to the generatrix of the second reflection component, and the angle between the first reflection component and the horizontal plane perpendicular to the optical axis (initial light beam) is θ. The refractive index of the materials of the first reflector 321 and the second reflector 322 satisfies n≥1 / sinθ.

[0068] At the same time, please refer to Figure 3 , the light beam I emitted by the VCSEL located at the lens object focus f position is parallelly emitted into a collimated light beam II after passing through the lens, and the diameter of the collimated light beam II is approximately equal to the lens aperture size D. In actual applications, it is found that the light spot of the collimated light beam under certain working current conditions is a circular ring distribution with a dark center and bright edges. After the light beam of this circular ring distribution passes through the first absorption unit 31, the light in the central area is almost completely absorbed, and the emitted light beam is a standard circular ring beam III with an outer diameter of D and an inner diameter of d (d is the disk diameter of the first absorption unit 31). The circular ring beam III then passes through the reflection unit 32, and the light in the inner ring area close to the center directly passes through the reflection unit 32, while the light in the outer ring area is blocked by the inner surface of the first reflector 321. Since the refractive index of the material of the reflection unit 32 satisfies n≥1 / sinθ, the light in the outer ring area is totally reflected. After further transmission, the reflected light is blocked by the outer surface of the second reflection unit 32 (the bottom circle diameter is d) in the center of the reflector, and is totally reflected again, and finally emitted from the center position perpendicular to the exit. This part of the light forms a beam with a diameter equal to d. The output beam IV of the final laser light source after passing through the reflection unit 32 has a diameter D ′=Dd circular distribution, that is, a laser light source with uniform energy distribution. Among them, the material refractive index n, height h and angle θ of the reflective unit 32 are interrelated, and the numerical values ​​of the other parameters can be calculated and solved after determining the value of one of the parameters according to actual needs. It should be noted that the necessity of designing the second absorption unit 33 in the reflective unit 32 in this example is that the outer wall of the reflective unit 32 needs to be extended and stretched as a connecting structure, and the central conical hole of the reflective unit 32 cannot be extended synchronously, otherwise it will cause the light near the center of the circular ring beam III formed by the first absorption unit 31 to enter the inner wall of the second reflector and refract. After this part of the light is emitted, the angle changes and it is no longer a parallel beam. The second absorption unit 33 designed as a truncated cone surface under the second reflector and painted with black paint on its inner wall can avoid this problem; at the same time, the stray light generated at the outermost edge during the transmission process can also be reflected by the outer inner wall of the reflective unit 32 to the cylindrical hole for absorption and filtering, so as to avoid the interference caused by multiple reflections and transmissions of the stray light in the reflective unit 32.

[0069] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it.

Claims

1. A uniform laser light source, characterized in that: include: A laser chip, used to emit the initial light beam; A collimating component, used for processing the initial light beam to obtain a collimated light beam; A homogenization component includes a first absorption unit and a reflection unit, wherein the first absorption unit is used to absorb light in a circular area in the middle of the collimated light beam, and the reflection unit is used to guide light in an annular area other than the circular area in the collimated light beam to an extension area along the circular area in the exit direction of the collimated light beam to form a uniform laser, and the light intensity distribution in the annular area of ​​the collimated light beam is uniform.

2. The uniform laser light source according to claim 1, characterized in that: The reflection unit comprises a first reflection mirror and a second reflection mirror, the reflection surface of the first reflection mirror is a truncated cone surface, the reflection surface of the second reflection mirror is a conical surface or a truncated cone surface, the reflection surface of the first reflection mirror and the reflection surface of the second reflection mirror have the same generatrix inclination angle, and the optical axis of the first absorption unit, the symmetry axis of the first reflection mirror, the symmetry axis of the second reflection mirror and the optical axis of the collimated light beam coincide with each other; The light in the annular area is reflected by the reflection surface of the first reflector to the reflection surface of the second reflector, and the reflection surface of the second reflector is used to reflect the light in the annular area to an extension area along the circular area in the direction of the collimated light beam emission to form the uniform laser.

3. The uniform laser light source according to claim 1, characterized in that: The reflection unit includes a first reflection mirror and a second reflection mirror, the reflection surface of the first reflection mirror is a truncated cone surface, the reflection surface of the second reflection mirror is a conical surface or a truncated cone surface, the reflection surface of the first reflection mirror and the reflection surface of the second reflection mirror have the same generatrix inclination angle, the annular region includes an inner ring region and an outer ring region having the same center, and the optical axis of the first absorption unit, the symmetry axis of the first reflection mirror, the symmetry axis of the second reflection mirror and the optical axis of the collimated light beam coincide with each other; The light in the outer ring area is reflected by the reflecting surface of the first reflector to the reflecting surface of the second reflector. The reflecting surface of the second reflector is used to reflect the light in the outer ring area to the extension area along the circular area in the exit direction of the collimated light beam. The light in the extension area and the light in the inner ring area form the uniform laser.

4. The uniform laser light source according to claim 2 or 3, characterized in that: The homogenization assembly further includes a second absorption unit, the outer surface of which is used to absorb stray light; The top surface diameter of the second absorption unit is the same as the diameter of the bottom surface circle of the second reflector, and the top surface of the second absorption unit is in contact with the bottom surface circle of the second reflector. The first end surface of the first absorption unit is a circle with the same diameter as the bottom surface of the second absorption unit, and the first end surface of the first absorption unit is in contact with the bottom surface of the second absorption unit.

5. The uniform laser light source according to claim 4, characterized in that: The outer surface of the second absorption unit, the second end surface of the first absorption unit away from the first end surface, and the side surface of the first absorption unit are coated with black paint, and the black paint is used to absorb light in a target band, where the target band is the band where the initial light beam is located.

6. The uniform laser light source according to claim 4, characterized in that: The bonding is a fixed connection or a detachable connection.

7. The uniform laser light source according to claim 2 or 3, characterized in that: The incident angle of the collimated light beam incident on the first reflector is greater than the corresponding total reflection angle, and the incident angle of the light beam incident on the second reflector is greater than the corresponding total reflection angle.

8. The uniform laser light source according to claim 2 or 3, characterized in that: The laser chip is electrically connected to the substrate; The uniform laser light source further includes: a mounting bracket, the substrate is fitted to one end of the mounting bracket, and the collimating assembly, the first reflector and the second reflector are arranged on the mounting bracket along the emitting direction of the collimated light beam.

9. The uniform laser light source according to claim 8, characterized in that: The mounting bracket includes a first bracket and a second bracket. The collimation assembly is arranged in the first bracket, and two ends of the first bracket are respectively attached to the substrate and the second bracket; The collimating assembly is arranged on the second bracket.

10. The uniform laser light source according to claim 1, characterized in that: The first bracket and the collimation assembly are integrally formed by an injection molding process or a hole digging process.

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