Light source module and dispersion confocal measurement device

Abstract

This invention discloses a light source module and a dispersion confocal measurement device. The light source module includes a light incident end, a light homogenizing plate, a confining dielectric layer, and a beam shaping block. The light incident end includes multiple fiber optic output ends, which are spaced apart along a first direction. The light homogenizing plate has a first refractive index, and its incident side is optically coupled to each fiber optic output end. The light homogenizing plate guides light to propagate along a second direction perpendicular to the first direction. At least one confining dielectric layer is disposed on at least one side surface of the light homogenizing plate, and has a second refractive index not greater than the first refractive index, so that the light undergoes total internal reflection within the light homogenizing plate. The beam shaping block is opposite to the light emitting side of the light homogenizing plate, and the light emitting side and the light emitting side are arranged opposite each other along the second direction. The beam shaping block is used to spatially filter the emitted light to output a target linear light. This solution can form a linear light with a highly uniform intensity distribution, ensuring the accuracy and reliability of optical measurements.

Description

Technical Field

[0001] This invention relates to the field of optical measurement, and in particular to a light source module and a dispersion confocal measurement device. Background Technology

[0002] Linear dispersion confocal measurement is a high-precision non-contact optical detection method. Its core lies in projecting a uniformly intense, clearly defined linear light beam onto the object being measured. To generate this type of linear light, existing technologies typically use a homogenizing plate to homogenize point or line light sources. Specifically, the light-emitting module includes a glass homogenizing plate. After light enters from one end of the homogenizing plate, it undergoes multiple total internal reflections between the two main surfaces of the plate to achieve uniform mixing within the plate, and then outputs linear light from the other end. However, the light in the homogenizing plate relies on total internal reflection at the glass-air interface for forward propagation. Only when the angle of incidence at the interface is greater than the critical angle of total internal reflection can the light be effectively confined within the plate. The beam emitted from an actual light source has a certain divergence angle. Light with an angle of incidence less than the critical angle will refract and leak at the interface; simultaneously, stray light generated by scattering and diffraction effects may also escape from the plate due to an angle of incidence that does not meet the total internal reflection condition. Furthermore, if the surface of the light homogenizer is contaminated or comes into contact with external objects, the conditions for total internal reflection will be disrupted, which will also cause light leakage. Light leakage not only reduces the efficiency of light energy utilization, but also makes it difficult to precisely control the light intensity distribution along the propagation direction inside the light homogenizer. This results in uneven brightness in the output linear light along its length, meaning the quality of the linear light formed is poor, which affects the accuracy of optical measurements. Summary of the Invention

[0003] The main objective of this invention is to propose a light source module and a dispersion confocal measurement device, which aims to solve the technical problem of poor linear light quality output by existing light source modules.

[0004] To achieve the above objectives, a first aspect of the present invention provides a light source module, the light source module comprising: The light incident end includes multiple optical fiber output ends, and each of the optical fiber output ends is arranged at intervals along a first direction; A light-diffusing plate having a first refractive index, wherein the light-incident side of the light-diffusing plate is optically coupled to the output end of each of the optical fibers, and the light-diffusing plate is used to guide light rays to propagate along a second direction perpendicular to the first direction; At least one confining medium layer is disposed on at least one side surface of the light homogenizing plate, the confining medium layer having a second refractive index not greater than the first refractive index, so that light undergoes total internal reflection within the light homogenizing plate; A beam shaping block is positioned opposite the light-emitting side of the light-diffusing plate. The light-emitting side and the light-incident side are arranged opposite each other along the second direction. The beam shaping block is used to perform spatial filtering on the emitted light to output target linear light.

[0005] In some embodiments, the constraint medium layer includes a first constraint medium plate and a second constraint medium plate, and the light-diffusing plate has a first outer side wall and a second outer side wall opposite to each other along its thickness direction; the first constraint medium plate is attached to the first outer side wall, and the second constraint medium plate is attached to the second outer side wall.

[0006] In some embodiments, the thickness of the first constraint medium plate is H1, the thickness of the second constraint medium plate is H2, and the thickness of the light-diffusing plate is H3. The first constraint medium plate and the light-diffusing plate satisfy the condition that H1 > H3, and the second constraint medium plate and the light-diffusing plate satisfy the condition that H2 > H3.

[0007] In some embodiments, along the second direction, the beam shaping block has an incident end face facing the light-emitting side, and the incident end face has a light-transmitting slit extending along the first direction. Along the thickness direction of the light-diffusing plate, the width of the light-transmitting slit is smaller than the thickness of the light-diffusing plate.

[0008] In some embodiments, the light source module further includes a fixing structure, which includes a first fixing plate and a second fixing plate opposite to each other, the first fixing plate and the second fixing plate cooperating to clamp and fix each of the optical fiber output ends.

[0009] In some embodiments, the light source module further includes a light-emitting element, a light guide element, and a beam gatherer element. The light guide element has a first light-inlet surface and a first light-outlet surface. The beam gatherer element is used to constrain the optical fibers into a bundle. The first light-inlet surface is optically coupled to the light-emitting element, and the first light-outlet surface is optically coupled to the multiple optical fiber input ends within the beam gatherer element.

[0010] In some embodiments, the light source module further includes a connector, the connector having a first cavity and a second cavity that are connected to each other, the light guide passing through the first cavity, and the beam gatherer passing through the second cavity.

[0011] In some embodiments, the light source module further includes a first positioning member, the connecting seat is provided with a first positioning hole communicating with the first cavity, the first positioning member passes through the first positioning hole and one end abuts against the light guide member; And / or, The light source module also includes a second positioning member. The connecting seat is provided with a second positioning hole that communicates with the second cavity. The second positioning member passes through the second positioning hole and one end abuts against the bundle member.

[0012] A second aspect of the present invention provides a dispersion confocal measurement device, the dispersion confocal measurement device comprising: The light source module as described in the above embodiments; The dispersive objective lens module is used to focus the linear light output from the light source module onto the object under test, and to disperse light of different wavelengths along the optical axis or non-axially. A spectral analysis module is used to receive light reflected from the object under test and analyze spectral information; The processing module calculates the height and / or thickness of the object under test based on the spectral information.

[0013] Compared with the prior art, the beneficial effects of the present invention include: In the technical solution of this invention, the light source module includes a light incident end, a light homogenizing plate, at least one confining dielectric layer, and a beam shaping block. The light incident end includes multiple fiber output ends, which are spaced apart along a first direction. The light homogenizing plate is optically coupled to the light output ends of each fiber, and the light homogenizing plate is used to guide the light to propagate along a second direction perpendicular to the first direction. In the prior art, the total internal reflection of the light homogenizing plate depends on the refractive index difference between glass and air, and its critical angle is relatively small. Even incident light at large angles will be totally internalized, resulting in a large divergence angle of the light emitted from the end face of the light homogenizing plate. This leads to blurred edges and insufficient sharpness of the light spot projected onto the object, i.e., poor quality of linear light, which affects the accuracy of optical measurements. In this scheme, the confinement medium layer is located on the side surface of the light homogenizer. The light homogenizer has a first refractive index, and the confinement medium layer has a second refractive index not greater than the first refractive index. This scheme allows for flexible modification of the physical conditions of the total internal reflection interface, increasing the critical angle for total internal reflection. For light rays with large propagation angles, they will be refracted at the light homogenizer-confinement medium layer interface and enter the confinement medium layer, subsequently projecting onto the outer surface of the confinement medium layer. Since the outer surface still satisfies the total internal reflection condition with air, the light is reflected and recoupled back to the light homogenizer, thus propagating back and forth between the light homogenizer and the two confinement medium layers with total internal reflection, preventing leakage to the outside. This scheme effectively isolates the surface of the light homogenizer, avoiding total internal reflection failure and light energy leakage caused by contact or contamination, improving system reliability and light energy utilization efficiency. Simultaneously, the total internal reflection confinement in this scheme allows light to undergo multiple reflections and mixing between the light homogenizer and the confinement medium layer, further eliminating local intensity differences at the input end caused by the discrete distribution of the fiber array, ensuring highly uniform linear light intensity distribution at the output side.

[0014] In existing technologies, light is emitted directly from the light-emitting surface at the end of a glass plate, and the cross-sectional shape of the output light spot is determined by the geometric contour of the glass plate end face, resulting in a relatively large spot width. In this solution, the beam shaping block is opposite to the light-emitting side of the homogenizing plate, and the light-emitting side and the light-incident side are arranged opposite each other along the second direction. The beam shaping block can spatially filter the emitted light, intercepting light rays emitted from a narrow strip region with a relatively uniform intensity distribution on the light-emitting surface of the homogenizing plate through physical blocking or limiting the beam cross-section, thereby outputting a narrower target linear light. Since the beam shaping block selectively passes the beam through its spatial position rather than filtering light rays at different propagation angles, light rays at various angles pass through the shaping block according to their original divergence characteristics, and the angular range of the emitted light rays still depends on the numerical aperture of the optical fiber. After this spatial filtering, the final output linear light has a sharp, well-defined edge and a highly uniform intensity distribution, effectively eliminating the blurred transition zone at the edge of the light spot and providing a clear and stable light source foundation for subsequent dispersive confocal measurements. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a light source module along one direction in one embodiment of the present invention; Figure 2 This is a schematic diagram of the light source module in one embodiment of the present invention along another direction; Figure 3 This is a partial cross-sectional view of the light source module in one embodiment of the present invention.

[0017] Explanation of icon numbers: Light source module 10; Optical input end 100; optical fiber output end 110; optical fiber input end 120; Light-diffusing plate 200; light-incident side 210; light-exiting side 220; first outer side wall 230; second outer side wall 240; Constraint medium layer 300; first constraint medium plate 310; second constraint medium plate 320; Beam shaping block 400; light entrance end surface 410; light exit end surface 420; Fixed structure 500; First fixed plate 510; Second fixed plate 520; Light-emitting component 600; Light guide 700; first light inlet surface 710; first light outlet surface 720; Cluster component 800; Connector 900; First positioning element 910; Second positioning element 920; First direction X; second direction Y.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] The first aspect of this invention provides a light source module 10 capable of generating uniform linear light. It should be noted that the light source module 10 can be used for dispersive confocal measurement or industrial inspection, etc. The following refers to... Figures 1 to 3 The light source module 10 of this application embodiment will be introduced. Specifically, the light source module 10 includes a light incident end 100, a light homogenizing plate 200, a confinement medium layer 300, and a beam shaping block 400.

[0021] It should be noted that the light incident end 100 refers to the light path relative to the light homogenizing plate 200. The light incident end 100 includes multiple fiber optic output ends 110, which can be an output array of a single-mode or multimode fiber bundle. The fiber optic output ends 110 do not necessarily have a corresponding order relative to the fiber optic input ends 120. To facilitate the description and understanding of the specific arrangement of each fiber optic output end 110, a first direction X is defined, referring to... Figure 1 In terms of orientation, the first direction X can be vertical, and the fiber output terminals 110 can be arranged at intervals along the first direction X. It can be understood that the first direction X is also the direction of extension of the length of the output linear light.

[0022] Reference Figure 2 The light homogenizer 200 enables uniform light emission. The incident side 210 of the light homogenizer 200 is optically coupled to the output ends 110 of each optical fiber. Optical coupling refers to the efficient transmission of light from one optical element to another. Specifically, optical coupling can be achieved through one or more of the following methods: direct physical contact between the end faces of the two optical elements; filling the gap between them with a refractive index matching liquid or optical adhesive; or connecting them after beam transformation using an intermediate optical element (such as a lens or prism). Optical coupling can minimize Fresnel reflection loss at the interface and improve light transmission efficiency.

[0023] The homogenizing plate 200 has a first refractive index. To facilitate the description and understanding of the propagation direction of light rays in the homogenizing plate 200, a second direction Y is defined, which is perpendicular to the first direction X. (Refer to...) Figure 1 The orientation, specifically the second direction Y, can be left or right, and the light-diffusing plate 200 can guide the light rays along its propagation path. It should be noted that the light-diffusing plate 200 can be a thin sheet of glass.

[0024] At least one confining medium layer 300 is disposed on at least one side surface of the light-diffusing plate 200, and the confining medium layer 300 serves to form a reflective interface. In some embodiments, the confining medium layer 300 may be a single layer. In other embodiments, the confining medium layer 300 may be multiple layers. This embodiment illustrates an example with two confining medium layers 300, each located on one side surface of the light-diffusing plate 200 along its thickness direction. The confining medium layer 300 has a second refractive index not greater than the first refractive index, so that light undergoes total internal reflection within the light-diffusing plate 200. It is understood that the confining medium layer 300 may be a high-density dielectric transparent plate. Specifically, the material of the confining medium layer 300 may be low-refractive-index optical glass or optical crystal material. It should be noted that the confining medium layer 300 may also be a specular reflective material or a specular reflective coating, so that light undergoes total internal reflection within the light-diffusing plate 200.

[0025] Total internal reflection is an optical phenomenon where light travels from a medium with a higher refractive index (optically denser medium) to a medium with a lower refractive index (optically less dense medium), and the angle of incidence is greater than a certain critical angle. In this application, the light-diffusing plate 200 has a first refractive index, and the confining medium layer 300 has a second refractive index not greater than the first refractive index. This refractive index relationship allows enhanced total internal reflection to occur at the interface between the light-diffusing plate 200 and the confining medium layer 300, effectively confining the light propagation within the light-diffusing plate 200.

[0026] The beam shaping block 400 is opposite to the light-emitting side 220 of the light-diffusing plate 200, and the light-emitting side 220 and the light-incident side 210 are arranged opposite each other along the second direction Y, as shown in the reference. Figure 2 In terms of orientation, the light-emitting side 220 can be located to the right of the homogenizing plate 200, the light-incident side 210 can be located to the left of the homogenizing plate 200, and the beam shaping block 400 can be located to the right of the light-emitting side 220 of the homogenizing plate 200. The beam shaping block 400 is used to spatially filter the emitted light to output the target linear light. It is understood that the material of the beam shaping block 400 can be the same as or different from that of the homogenizing plate 200. For example, the material of the beam shaping block 400 can be glass, metal (such as stainless steel, Invar alloy), or a combination of both.

[0027] It should be noted that spatial filtering refers to the process of filtering and shaping the spatial distribution (including positional and angular distribution) of a light beam in an optical system. Unlike wavelength filtering (which filters light of a specific color or wavelength), spatial filtering acts on the propagation path and direction of light. It can be understood that the target linear beam refers to a linear light spot that meets the requirements of a specific application scenario. In the dispersive confocal measurement application scenario of this application, the target linear beam can be: a beam extending in a thin strip along the first direction X, with highly uniform light intensity distribution along its length, sharp and clear spot boundaries, and good consistency in the emission direction. For example, the cross-sectional width of the target linear beam can be on the order of micrometers, and its length can be from several millimeters to tens of millimeters.

[0028] In the technical solution of this invention, the light source module 10 includes a light incident end 100, a light homogenizing plate 200, at least one confinement dielectric layer 300, and a beam shaping block 400. The light incident end 100 includes multiple fiber output ends 110, which are spaced apart along a first direction X. The light incident side 210 of the light homogenizing plate 200 is optically coupled to each fiber output end 110, and the light homogenizing plate 200 is used to guide light to propagate along a second direction Y perpendicular to the first direction X. In the prior art, the total internal reflection of the light homogenizing plate depends on the refractive index difference between glass and air, and its critical angle is relatively small. Even incident light at large angles will be totally internalized, resulting in a large divergence angle of the light emitted from the end face of the light homogenizing plate. This leads to blurred edges and insufficient sharpness of the light spot projected onto the object, i.e., poor quality of linear light, which affects the accuracy of optical measurements. In this design, the confining medium layer 300 is disposed on the side surface of the light homogenizing plate 200. The light homogenizing plate 200 has a first refractive index, and the confining medium layer 300 has a second refractive index not greater than the first refractive index. This design allows for flexible modification of the physical conditions of the total internal reflection interface. Increasing the critical angle of total internal reflection allows light rays with larger propagation angles to be refracted at the interface between the light homogenizing plate 200 and the confining medium layer 300 and enter the confining medium layer 300, subsequently projecting onto the outer surface of the confining medium layer 300. Since the outer surface still satisfies the total internal reflection condition with air, the light is reflected and recoupled back to the light homogenizing plate 200, thus propagating back and forth between the light homogenizing plate 200 and the two confining medium layers 300 via total internal reflection, preventing leakage to the outside. This design effectively isolates the surface of the light homogenizing plate 200, avoiding total internal reflection failure and light energy leakage due to contact or contamination, thereby improving the system's reliability and light energy utilization efficiency. Meanwhile, the total internal reflection constraint of this scheme enables the light to undergo multiple reflections and mixing between the light homogenizing plate 200 and the constraint medium layer 300, further eliminating the local light intensity differences caused by the discrete distribution of the fiber array at the input end, and ensuring that a linear light with a highly uniform light intensity distribution is obtained on the light output side 220.

[0029] In addition, in the prior art, light is emitted directly from the light-emitting surface at the end of the glass plate, and the cross-sectional shape of the output light spot is determined by the geometric contour of the glass plate end face, resulting in a relatively large light spot width. In this solution, the beam shaping block 400 is opposite to the light-emitting side 220 of the homogenizing plate 200, and the light-emitting side 220 is arranged opposite to the light-incident side 210 along the second direction Y. The beam shaping block 300 can perform spatial filtering on the emitted light. By physically blocking or limiting the beam cross-section, it intercepts the light emitted from a narrow strip area with a relatively uniform light intensity distribution on the light-emitting surface of the homogenizing plate 200, thereby outputting a target linear light with a narrower width. Since the beam shaping block 300 selectively passes the light beam through its spatial position rather than filtering light at different propagation angles, light at various angles passes through the beam shaping block 400 according to its original divergence characteristics, and the angular range of the emitted light still depends on the numerical aperture of the optical fiber. After this spatial filtering, the final output linear light has a sharp edge with a distinct outline and a highly uniform light intensity distribution, which can effectively eliminate the blurry transition area at the edge of the light spot and provide a clear and stable light source foundation for subsequent dispersive confocal measurements.

[0030] The specific configuration of the constraint medium layer 300 is described below. In some embodiments, the constraint medium layer 300 includes a first constraint medium plate 310 and a second constraint medium plate 320, as shown below. Figure 2 In terms of orientation, the first constraint medium plate 310 can be located above the light-diffusing plate 200, and the second constraint medium plate 320 can be located below the light-diffusing plate 200. The light-diffusing plate 200 has opposing first outer sidewalls 230 and second outer sidewalls 240 along its thickness direction, as shown in the reference section. Figure 2 In terms of orientation, the upper sidewall of the light-diffusing plate 200 can be a first outer sidewall 230, and the lower sidewall of the light-diffusing plate 200 can be a second outer sidewall 240. A first constraint dielectric plate 310 is attached to the first outer sidewall 230, and a second constraint dielectric plate 320 is attached to the second outer sidewall 240. In some embodiments, the constraint dielectric plate can be omitted, and a high-reflectivity optical thin film can be symmetrically deposited on the first outer sidewall 230 and the second outer sidewall 240 of the light-diffusing plate 200. In other embodiments, the constraint dielectric plate can be omitted, and the light-diffusing plate 200 can be immersed in a low-refractive-index matching liquid, the refractive index of which is less than or equal to the first refractive index of the light-diffusing plate 200.

[0031] It should be noted that in some embodiments, the first constraint medium plate 310 can be attached to the first outer wall 230 via optical adhesive. Optical adhesive refers to applying an optical-grade transparent adhesive between the mating surfaces of two optical elements, and bonding them together through the curing of the adhesive. In other embodiments, the first constraint medium plate 310 can be attached to the first outer wall 230 via photoadhesive. Photoadhesive is an optical contact bonding technology without an intermediate medium. It utilizes the intermolecular forces (van der Waals forces) between two ultra-precision polished surfaces to achieve adsorption bonding without any adhesive. In other embodiments, the first constraint medium plate 310 can be attached to the first outer wall 230 via direct bonding. Direct bonding is a technology that connects two solid surfaces together through atomic-level chemical bonds. Direct bonding forms true covalent or ionic bonds at the interface, with a bonding strength close to that of the parent material itself. This application uses the example of the first constraint medium plate 310 being attached to the first outer wall 230 via optical adhesive for illustration. It is understandable that the bonding configuration of the second constraint medium plate 320 with the light uniform plate 200 can be the same as the bonding configuration of the first constraint medium plate 310 with the light uniform plate 200.

[0032] In industrial applications of dispersive confocal measurement, the light source module 10 often needs to operate continuously for hours or even hundreds of hours. Although both the homogenizing plate 200 and the constraint dielectric plate are made of glass, their coefficients of thermal expansion have slight differences. If the constraint dielectric plate is only attached to one side of the homogenizing plate 200 (i.e., a single-sided constraint scheme), under prolonged high-power illumination, the temperature rise of the homogenizing plate 200 and the constraint dielectric plate will be inconsistent. Combined with their different coefficients of thermal expansion, this will cause the entire "double-layer" structure to bend and warp. This warping will not only compromise the alignment accuracy between the fiber array and the incident light side 210 of the homogenizing plate 200, but will also introduce stress birefringence within the homogenizing plate 200. That is, the originally isotropic glass material becomes anisotropic under stress, causing differences in the propagation speed of light in different polarization directions, ultimately disrupting the uniformity of the emitted light spot. This scheme symmetrically arranges a first constraint dielectric plate 310 and a second constraint dielectric plate 320. Furthermore, since the constraint medium plates on both sides are made of the same material, have the same thickness, and are bonded using the same process, the thermal stresses generated on both sides are equal in magnitude and opposite in direction when the temperature changes, thus canceling each other out. As an intermediate layer, the uniform light plate 200 experiences net stress close to zero, thereby effectively suppressing thermal warping and stress birefringence.

[0033] The relative thickness settings of the constraint medium plate and the light-diffusing plate 200 are described below. In some embodiments, the thickness of the first constraint medium plate 310 is H1, the thickness of the second constraint medium plate 320 is H2, and the thickness of the light-diffusing plate 200 is H3. The first constraint medium plate 310 and the light-diffusing plate 200 satisfy: H1 > H3; the second constraint medium plate 320 and the light-diffusing plate 200 satisfy: H2 > H3. That is, the thickness of both the first constraint medium plate 310 and the second constraint medium plate 320 is greater than the thickness of the light-diffusing plate 200. For example, the thickness of the constraint medium plate can be 2 to 4 times the thickness of the light-diffusing plate 200. In other embodiments, the thickness of the first constraint medium plate 310 can be the same as or different from the thickness of the second constraint medium plate 320, depending on the actual needs.

[0034] This scheme adjusts the total internal reflection constraint by adjusting the refractive index of the constraint medium plate. During total internal reflection, the light field penetrates into the vicinity of the surface of the optically rarefied medium (i.e., the constraint medium plate in this scheme) in the form of an evanescent wave. The electric field intensity of the evanescent wave decreases exponentially with the penetration depth. Since the thicknesses of the first constraint medium plate 310 and the second constraint medium plate 320 are both greater than the thickness of the light homogenizing plate 200, the energy of the evanescent wave attenuates inside the constraint medium plate and does not penetrate to the outer surface of the constraint medium plate and leak into the outside air. Furthermore, the thicker constraint medium plate provides ample "buffer space," allowing the outer surface of the constraint medium plate to be frosted or coated with a black light-absorbing layer during processing and assembly to eliminate stray light without affecting the optical quality of the total internal reflection interface. Additionally, because the light homogenizing plate 200 itself is relatively thin and has limited mechanical strength, it is easily bent or broken by external forces during assembly and transportation. In this embodiment, the thicker constraint medium plate is attached to both sides of the light-diffusing plate 200, which acts as a structural reinforcement plate. That is, the light-diffusing plate 200 can be clamped between two thick plates, and the overall bending stiffness is significantly improved.

[0035] In some embodiments, the thickness of the first constraint medium plate 310 and the thickness of the second constraint medium plate 320 are both equal to the thickness of the light homogenizing plate 200. However, light absorption layers are respectively provided on the outer surfaces of the first constraint medium plate 310 and the second constraint medium plate 320. The light absorption layers may be black chromium plating, carbon nanotube coating, or black anodized layer. Although the thickness of the constraint medium plate in this embodiment is insufficient to completely attenuate evanescent waves, any weak light penetrating to the outer surface is efficiently absorbed by the light absorption layer, thereby preventing it from reflecting back into the optical path and forming stray light. In other embodiments, the thickness of the constraint medium plate may be less than the thickness of the light homogenizing plate 200. However, the outer surface of the constraint medium plate is provided with a high-reflectivity dielectric film or a metal reflective film (such as an aluminum film, a silver film, or a dielectric high-reflectivity film). Even if light penetrates the thinner constraint medium plate, it will be forcibly reflected by the high-reflectivity film when it reaches the outer surface, and then pass through the constraint medium plate again to return to the light homogenizing plate 200. In other embodiments, the light intensity distribution of the light homogenizing plate 200 along the second direction Y may need to be non-uniformly controlled. At this point, the thickness of the first constraint dielectric plate 310 and / or the second constraint dielectric plate 320 can be designed to gradually change along the second direction Y. For example, the thickness is larger near the light incident end 100 and gradually decreases near the light emitting side 220. This scheme can fine-tune the evanescent wave leakage rate in a local area by controlling the local thickness of the constraint dielectric plate, thereby actively compensating for the light intensity attenuation of the uniform light plate 200 along the propagation direction and achieving a more ideal flat-top light intensity distribution.

[0036] In some embodiments, along the second direction Y, the beam shaping block 400 has an incident end face 410 facing the light-emitting side 220, as shown in the reference. Figure 2 In terms of orientation, the light-incident end face 410 is located to the left of the beam shaping block 400. The light-incident end face 410 has a light-transmitting slit extending along the first direction X, as shown in the reference diagram. Figure 1 The orientation, specifically the first direction X, can be vertical. This can be understood as the arrangement direction of the fiber optic output ends 110, and also the length direction of the final output linear light. The length of the light-transmitting slit along the first direction X matches the arrangement length of the fiber array, ensuring that the light emitted from all fiber optic output ends 110 is covered by the slit. Along the thickness direction of the light-diffusing plate 200, the width of the light-transmitting slit is less than the thickness of the light-diffusing plate 200. (Refer to...) Figure 2In terms of orientation, i.e., along the vertical direction, the width of the light-transmitting slit is less than the thickness of the homogenizing plate 200. For example, the width of the light-transmitting slit can be 1 / 6 to 1 / 2 of the thickness of the homogenizing plate 200. The light beam emitted from the light-emitting side 220 of the homogenizing plate 200 is not entirely ideally parallel. Due to multiple total internal reflections within the homogenizing plate 200, the emitted light contains a rich variety of angular components. A portion of the light, after sufficient homogenization, propagates almost parallel to the second direction Y (i.e., the angle with the optical axis is extremely small), and can be called axial light; another portion of the light, due to interface scattering, defect diffraction, or insufficient mixing, deviates from the second direction Y at a larger angle, and can be called large-angle stray light. When this beam of light containing multiple angular components reaches the light-incident end face 410 of the beam shaping block 400, the light-transmitting slit can shape the shape of the light source. Specifically, only light with a propagation angle less than a certain threshold with the second direction Y can pass smoothly through the slit. Furthermore, by setting a light-transmitting slit with a width less than 200 mm thick of the light-diffusing plate, this embodiment can effectively suppress stray light in the thickness direction.

[0037] In other embodiments, the beam shaping block 400 may have two light-transmitting slits spaced apart along the second direction Y. The first light-transmitting slit is located on the light-incident end face 410, and the second light-transmitting slit is located on the middle partition plate inside the beam shaping block 400. In this solution, the first light-transmitting slit can shape the shape of the light source. After the selected beam has propagated a certain distance inside the beam shaping block 400, some of the light rays that still have slight angular deviations will be blocked when they reach the second light-transmitting slit due to positional shift. This allows for more stringent divergence angle control within a limited physical space.

[0038] In other embodiments, the light-transmitting slit can be designed with a gradually varying width along the first direction X. For example, the width of the light-transmitting slit at both ends is slightly larger than the width in the middle, forming a distribution that is "narrow in the middle and slightly wider at both ends". In actual fiber array coupling scenarios, the intensity distribution of emitted light from the light-diffusing plate 200 along the first direction X may have slight non-uniformity, such as the light intensity being slightly higher in the middle region and slightly lower at both ends due to edge effects. This solution, by designing the light-transmitting slit with a gradually varying width, can apply stronger spatial filtering (narrower slit) in the middle region where the light intensity is higher, and appropriately relax the restriction (slightly wider slit) in the two ends where the light intensity is lower. This achieves angle filtering while actively compensating for the non-uniformity of light intensity, resulting in a linear light with a flatter intensity distribution.

[0039] It should be noted that the processing method of the light-transmitting slit can be selected according to the material of the beam shaping block 400. When the beam shaping block 400 is made of metal (such as stainless steel or Invar alloy), the light-transmitting slit can be processed by precision wire cutting or laser cutting. When the beam shaping block 400 is made of glass, a metal mask layer (such as a chromium film) can be deposited on the light-incident end face 410 first, and then the light-transmitting slit can be etched by photolithography.

[0040] Reference Figure 2 In some embodiments, the light source module 10 further includes a fixing structure 500 for fixing the fiber array. Specifically, the fixing structure 500 includes a first fixing plate 510 and a second fixing plate 520 opposite to each other. In some embodiments, the first fixing plate 510 can directly cooperate with the second fixing plate 520 to clamp and fix each fiber output end 110. In other embodiments, the first fixing plate 510 is provided with a plurality of first serrations distributed along a first direction X, and the second fixing plate 520 is provided with a plurality of second serrations distributed along the first direction X. The plurality of first serrations and the plurality of second serrations are interleaved to clamp and fix each fiber output end 110. It is understood that the materials of the first fixing plate 510 and the second fixing plate 520 can be metal materials (such as stainless steel, aluminum alloy, Invar alloy), ceramic materials (such as alumina, aluminum nitride), or silicon-based materials, depending on the actual situation. The cross-sectional shape of the serrations can be triangular, trapezoidal, or rectangular. When it is necessary to fix the optical fiber, the valley position of the first sawtooth can correspond to the peak position of the second sawtooth, and vice versa. When the first fixing plate 510 and the second fixing plate 520 approach and press against each other, multiple V-shaped clamping grooves are formed between the valley of the first sawtooth and the peak of the second sawtooth, spaced apart along the first direction X. The size and shape of each V-shaped clamping groove can accommodate the output end of one optical fiber. Each optical fiber in this scheme is positioned at three or four points, for example, the circumferential surface of the optical fiber is simultaneously in contact with two sides of the first sawtooth and at least one side (or valley surface) of the second sawtooth. This multi-point contact positioning method makes the position of the optical fiber in the clamping groove accurately positioned, and its axial position has high repeatability. At the same time, since the sawtooth is continuously distributed along the first direction X, the spacing between each optical fiber is precisely determined by the tooth pitch, which can ensure the uniformity of the optical fiber array along the first direction X.

[0041] In some embodiments, the first fixing plate 510 has a plurality of first serrations distributed along the first direction X, while the second fixing plate 520 adopts an elastic pressure block structure. The elastic pressure block is made of an elastic material (such as silicone rubber, fluororubber) or spring steel sheet, and its surface is flat or has an arc-shaped groove matching the outer diameter of the optical fiber. During assembly, the first serrations precisely position each optical fiber, and the elastic pressure block applies uniform pressure from the other side to press the optical fiber tightly into the serration groove. The deformation of the elastic pressure block can compensate for the small tolerance difference of the outer diameter of the optical fiber, while providing a certain vibration damping effect. This solution has a higher tolerance for the outer diameter tolerance of the optical fiber, better assembly tolerance, and is suitable for mass production scenarios. In other embodiments, the fixing structure 500 includes an optical fiber positioning comb and a pressure plate. The optical fiber positioning comb can be a thin plate-shaped part with a plurality of U-shaped or V-shaped through slots arranged at equal intervals along the first direction X. Each optical fiber output end 110 is embedded in the corresponding through slot. The pressure plate can cover the positioning comb and enclose the optical fiber in the through slot. The through-slots in this solution can be processed by precision electroforming, laser cutting or deep reactive ion etching. The processing technology is mature, the precision is controllable, and the positioning comb can be pre-assembled and tested independently of the light uniform plate 200, with a high degree of modularity.

[0042] Reference Figure 1 and Figure 2 In some embodiments, the light source module 10 further includes a light-emitting element 600, a light guide 700, and a bundler 800. The light-emitting element 600 is the primary light source of the light source module 10. Specifically, the light-emitting element 600 can be an LED, VCSEL, a combination of a laser diode and phosphor, a blue LED and phosphor combination, a halogen lamp, or a xenon lamp, etc. The light guide 700 has a first light-inlet surface 710 and a first light-outlet surface 720. The bundler 800 may have a cavity for each optical fiber to pass through, and the bundler 800 can constrain the optical fibers into a bundle. The first light-inlet surface 710 can be optically coupled to the light-emitting element 600, and the first light-outlet surface 720 can be optically coupled to multiple optical fiber input ends 120 within the bundler 800. The light guide 700 can be a cylindrical or prismatic light guide rod made of optical glass or quartz glass, etc. The bundler 800 can be a metal sleeve. The light guide 700 in this design enables a high-density light spot near the surface of the light-emitting element 600 to extend axially in space. The light energy is expanded from being concentrated on the surface of the light-emitting element, which is only a few micrometers thick, to being distributed across the entire length of the light guide 700. This is similar to converting a point heat source into a line heat source, significantly reducing the heat load per unit length.

[0043] In some embodiments, the light source module 10 further includes a connector 900, which has a first cavity and a second cavity communicating with each other. The first cavity and the second cavity are arranged opposite to each other along a second direction Y. A light guide 700 passes through the first cavity, and a beam gatherer 800 passes through the second cavity. It should be noted that the shape and size of the first cavity can match the shape of the light guide 700. For example, when the light guide 700 is a cylindrical light guide rod, the first cavity is a cylindrical through hole or blind hole. The shape and size of the second cavity can match the shape of the beam gatherer 800. For example, when the beam gatherer 800 is a frustum, the second cavity is a corresponding frustum cavity. The first cavity and the second cavity form a stepped surface or a conical surface transition at their interface. When the light guide 700 and the bundler 800 are inserted into the connector 900 from both ends, the light guide 700 and the opposite end face of the light incident end 100 (i.e., the first light emitting surface 720 of the light guide 700 and the optical fiber input end 120) meet and abut against each other at the junction, forming an optical coupling connection.

[0044] In this design, a defined axial reference plane can be formed at the junction of the first and second cavities. When the light guide 700 and the beam gatherer 800 are inserted from both ends and abut against this plane, the end face gap between them is mechanically forced to zero, ensuring long-term positional stability even without relying on the adhesive layer. Furthermore, the inner walls of the first and second cavities provide continuous circumferential constraints for the light guide 700 and the beam gatherer 800, ensuring that their optical axes remain coaxial. In addition, since the connecting seat 900 is an integral structure, its thermal expansion is isotropic. When the temperature changes, the apertures of the first and second cavities change synchronously, and the positions of the light guide 700 and the beam gatherer 800 within the cavities are adjusted uniformly accordingly, minimizing relative misalignment.

[0045] Reference Figure 3In some embodiments, the light source module 10 further includes a first positioning member. The connecting seat 900 has a first positioning hole communicating with the first cavity. The first positioning member can pass through the first positioning hole and abut one end against the light guide 700. Specifically, the first positioning member can be a set screw, screw, or threaded rod, etc. This solution eliminates the gap between the light guide 700 and the inner wall of the first cavity through the first positioning member, so that the light guide 700 is firmly pressed against one side of the inner wall of the cavity, and its radial position is uniquely determined, no longer subject to slight shaking due to vibration or temperature changes. In addition, the pressing of the first positioning member can also play a circumferential anti-rotation role, preventing the light guide 700 from rotating and misaligning within the cavity. Furthermore, the operator can precisely adjust the pressing force by controlling the screw-in depth, ensuring sufficient fastening effect while avoiding excessive stress that could cause deformation of the optical element or stress birefringence. In other embodiments, there are two first positioning members, symmetrically arranged on both sides of the connecting seat 900. In other embodiments, the first positioning member can be an elastic positioning member. In some embodiments, magnetic material layers are respectively provided on the outer wall surface of the light guide 700 and the inner wall surface of the first cavity of the connector 900. For example, a magnetic thin film (such as a neodymium iron boron thin film) is deposited on the surface of the light guide 700, and a permanent magnet sheet is embedded in the inner wall of the cavity. When the light guide 700 enters the cavity, magnetic attraction automatically attracts it to one side of the inner wall of the cavity, achieving non-contact radial positioning.

[0046] Reference Figure 3 In some embodiments, the light source module 10 further includes a second positioning member. The connecting seat 900 has a second positioning hole communicating with the second cavity. The second positioning member can pass through the second positioning hole and abut one end against the cluster member 800. Specifically, the second positioning member can be a set screw, screw, or threaded rod, etc. This solution eliminates the fit gap between the cluster member 800 and the inner wall of the second cavity through the second positioning member, so that the cluster member 800 is firmly pressed against one side of the inner wall of the cavity, and its radial position is uniquely determined, no longer subject to slight shaking due to vibration or temperature changes. In addition, the pressing of the second positioning member can also play a circumferential anti-rotation role, preventing the cluster member 800 from rotating and misaligning within the cavity. Furthermore, the operator can precisely adjust the pressing force by controlling the screw-in depth, ensuring sufficient fastening effect while avoiding excessive stress that could cause deformation of the optical element or stress birefringence. In other embodiments, two second positioning members are provided, symmetrically arranged on both sides of the connecting seat 900. In other embodiments, the second positioning member can be an elastic positioning member. In some embodiments, magnetic material layers are respectively provided on the outer wall surface of the cluster member 800 and the inner wall surface of the first cavity of the connector 900. For example, a magnetic thin film (such as a neodymium iron boron thin film) is deposited on the surface of the cluster member 800, and a permanent magnet sheet is embedded in the inner wall of the cavity. When the cluster member 800 is inserted into the cavity, magnetic attraction automatically attracts it to one side of the inner wall of the cavity, achieving contactless radial positioning.

[0047] A second aspect of this invention provides a dispersive confocal measurement device, which includes the light source module 10 described in the above embodiment, and further includes a dispersive objective lens module, a spectral analysis module, and a processing module. The dispersive objective lens module focuses the linear light output from the light source module 10 onto the object under test, and disperses light of different wavelengths along the optical axis or non-axially. The spectral analysis module receives the light reflected from the object under test and analyzes the spectral information. The processing module calculates the height and / or thickness of the object under test based on the spectral information.

[0048] Specifically, the light source module 10 provides high-quality, linearly uniform light for the entire measuring device. As described in the preceding embodiments, the light source module 10, through fiber array input, enhanced total internal reflection uniform light by the constraint dielectric layer 300, and spatial filtering by the beam shaping block 400, can output linear light with a sharp spot boundary that extends uniformly along the first direction X. The dispersive objective module is disposed on the light-emitting side 220 of the light source module 10, located between the light source module 10 and the object under test. The dispersive objective module includes at least one optical element with axial dispersion characteristics (such as a dispersive lens, a diffractive optical element, or a refractive-diffractive hybrid element). The function of the dispersive objective module is to receive the linearly uniform light output by the light source module 10 and focus it onto the surface of the object under test. Due to its axial dispersion characteristics, light of different wavelengths is focused at different height positions along the optical axis, forming a "rainbow focal line" extending along the optical axis. The spectral analysis module is disposed on the receiving side of the reflected light path. Light reflected (or scattered) from the surface of the object under test returns along the original optical path, is collected by the dispersive objective lens module, and then guided into the spectral analysis module through a beam splitter or optical circulator. The spectral analysis module includes a beam splitter (such as a grating, prism, or diffraction grating) and a photodetector (such as a linear CMOS or CCD sensor). The beam splitter disperses the received polychromatic light spatially according to wavelength, and the photodetector records the light intensity signal corresponding to each wavelength, forming a spectral distribution curve. The processing module is electrically connected to the spectral analysis module, receives the spectral data, and processes it. The processing module includes signal processing circuitry (such as an amplifier or analog-to-digital converter) and a computation unit (such as a microprocessor, digital signal processor, or field-programmable gate array). The computation unit executes a predetermined algorithm to perform peak detection, wavelength calibration, and height conversion on the spectral curve, ultimately calculating the height information of the surface of the object under test and / or the thickness information of transparent materials. This solution can significantly reduce light leakage loss, improve light energy utilization, and form linear light with highly uniform intensity distribution. It can significantly improve the boundary clarity and spatial directivity of the light spot, and avoid stray light interference with measurement accuracy, thus ensuring the accuracy and reliability of optical measurements.

[0049] It should be noted that if directional indications (such as up, down, left, right, front, back, etc.) are involved in the embodiments of the present invention, these directional indications are only used to explain the relative positional relationships and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. When a direction reference is introduced in a specific embodiment, unless the direction is specifically limited to unidirectional, the direction can be unidirectional or bidirectional (two parallel and opposite directions). Whether it is unidirectional or bidirectional depends on what those skilled in the art can achieve. When the direction reference is bidirectional, it should be considered that two parallel and different embodiments have been introduced simultaneously.

[0050] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0051] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A light source module, characterized in that, include: The light incident end includes multiple optical fiber output ends, and each of the optical fiber output ends is arranged at intervals along a first direction; A light-diffusing plate having a first refractive index, wherein the light-incident side of the light-diffusing plate is optically coupled to the output end of each of the optical fibers, and the light-diffusing plate is used to guide light rays to propagate along a second direction perpendicular to the first direction; At least one confining medium layer is disposed on at least one side surface of the light homogenizing plate, the confining medium layer having a second refractive index not greater than the first refractive index, so that light undergoes total internal reflection within the light homogenizing plate; A beam shaping block is positioned opposite the light-emitting side of the light-diffusing plate. The light-emitting side and the light-incident side are arranged opposite each other along the second direction. The beam shaping block is used to perform spatial filtering on the emitted light to output target linear light.

2. The light source module as described in claim 1, characterized in that, The constraint medium layer includes a first constraint medium plate and a second constraint medium plate. The light-diffusing plate has a first outer side wall and a second outer side wall opposite to each other along its thickness direction. The first constraint medium plate is attached to the first outer side wall, and the second constraint medium plate is attached to the second outer side wall.

3. The light source module as described in claim 2, characterized in that, The thickness of the first constraint medium plate is H1, the thickness of the second constraint medium plate is H2, and the thickness of the light-diffusing plate is H3. The first constraint medium plate and the light-diffusing plate satisfy the condition that H1 > H3, and the second constraint medium plate and the light-diffusing plate satisfy the condition that H2 > H3.

4. The light source module as described in claim 1, characterized in that, Along the second direction, the beam shaping block has an incident end face facing the light-emitting side, and the incident end face has a light-transmitting slit extending along the first direction. Along the thickness direction of the light-diffusing plate, the width of the light-transmitting slit is smaller than the thickness of the light-diffusing plate.

5. The light source module as described in claim 1, characterized in that, The light source module also includes a fixing structure, which includes a first fixing plate and a second fixing plate that are opposite to each other. The first fixing plate and the second fixing plate cooperate to clamp and fix each of the optical fiber output ends.

6. The light source module as described in claim 1, characterized in that, The light source module further includes a light-emitting element, a light guide element, and a beam gatherer element. The light guide element has a first light inlet surface and a first light outlet surface. The beam gatherer element is used to constrain the optical fibers into a bundle. The first light inlet surface is optically coupled to the light-emitting element, and the first light outlet surface is optically coupled to the multiple optical fiber input ends within the beam gatherer element.

7. The light source module as described in claim 6, characterized in that, The light source module also includes a connector, which has a first cavity and a second cavity that are connected to each other. The light guide is inserted into the first cavity and the beam gatherer is inserted into the second cavity.

8. The light source module as described in claim 7, characterized in that, The light source module further includes a first positioning member, and the connecting seat is provided with a first positioning hole communicating with the first cavity. The first positioning member passes through the first positioning hole and one end abuts against the light guide member. And / or, The light source module also includes a second positioning member. The connecting seat is provided with a second positioning hole that communicates with the second cavity. The second positioning member passes through the second positioning hole and one end abuts against the bundle member.

9. A dispersive confocal measuring device, characterized in that, include: The light source module as described in any one of claims 1-8; The dispersive objective lens module is used to focus the linear light output from the light source module onto the object under test, and to disperse light of different wavelengths along the optical axis or non-axially. A spectral analysis module is used to receive light reflected from the object under test and analyze spectral information; The processing module calculates the height and / or thickness of the object under test based on the spectral information.

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