A light homogenizing and speckle eliminating system using optical waveguide and inverted pyramid-shaped reflection cavity

Abstract

The application discloses a light uniforming and speckle eliminating system using an optical waveguide and an inverted-pyramid-shaped reflecting cavity, which comprises a hollow reflecting circular truncated cone, a circular truncated cone-shaped hollow reflecting cavity, an optical waveguide bundle, an inverted-pyramid-shaped hollow reflecting cavity and a light uniforming sheet, the hollow reflecting circular truncated cone is arranged at a light inlet of the circular truncated cone-shaped hollow reflecting cavity, and the optical waveguide bundle is arranged between the circular truncated cone-shaped hollow reflecting cavity and the inverted-pyramid-shaped hollow reflecting cavity or encapsulated in the inverted-pyramid-shaped hollow reflecting cavity.In the application, the light reflected by the circular truncated cone-shaped hollow reflecting cavity is incident into the optical waveguide bundle at a certain angle with the horizontal optical axis, so that the spatial coherence of the laser is reduced, and the speckle is inhibited; the light incident into the optical waveguide bundle is continuously reflected and scattered in the waveguide to further inhibit the speckle noise, and the light uniforming effect is achieved; and the light is uniformly lighted again by the light uniforming sheet, so that the light uniforming and speckle eliminating system can be used for light uniforming and speckle eliminating of a large-aperture collimated light beam, no vibration is generated, the cost is low, and the system is suitable for industrial popularization and use.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of laser illumination, and particularly relates to a uniform light dissipation speckle system using an optical waveguide and an inverted-pyramid-shaped reflection cavity. BACKGROUND

[0002] An illumination imaging light source is a major research direction in the imaging field, and an ideal illumination imaging light source needs to have the characteristics of low coherence, high spectral density and high brightness output. Most illumination light sources adopt LEDs, but the spectral density and brightness of the LED light source are low. Laser gradually becomes a research hotspot and replaces the traditional LED light source in some applications due to its own characteristics of high brightness and high monochromaticity.

[0003] However, it is worth noting that the laser has high coherence, and the light beam is Gaussian distribution, so the illumination distribution is uneven, and the coherent noise (speckle) is serious, which will reduce the imaging quality and illumination quality. Therefore, how to reduce the speckle noise and improve the illumination uniformity is a very important problem.

[0004] The traditional uniform light dissipation speckle scheme can be roughly summarized as follows:

[0005] 1. Using a vibrating microlens array (compound eye lens) and a uniform light sheet;

[0006] 2. Using a vibrating multi-mode fiber bundle and a uniform light sheet;

[0007] 3. Using a diffraction element and a lens group.

[0008] In the above-mentioned schemes, most of them will introduce a vibrating structure, which will bring mechanical vibration to the whole system, and the design of the structure will also have higher requirements, and the use of a diffraction element has a high cost and generally needs to be customized, and the time period is longer. SUMMARY

[0009] To solve the technical problems existing in the prior art, the purpose of the present application is to provide a uniform light dissipation speckle system using an optical waveguide and an inverted-pyramid-shaped reflection cavity.

[0010] To achieve the above-mentioned purposes and achieve the above-mentioned technical effects, the technical scheme adopted by the present application is as follows:

[0011] The application discloses a light homogenizing and spot dissipating system using an optical waveguide and an inverted-pyramid-shaped reflecting cavity, which comprises a hollow reflecting circular truncated cone, a circular truncated cone-shaped hollow reflecting cavity, an optical waveguide bundle, an inverted-pyramid-shaped hollow reflecting cavity and a light homogenizing sheet, wherein the circular truncated cone-shaped hollow reflecting cavity, the inverted-pyramid-shaped hollow reflecting cavity and the light homogenizing sheet are sequentially arranged along the light incidence direction, the hollow reflecting circular truncated cone is arranged at a light inlet of the circular truncated cone-shaped hollow reflecting cavity, the light inlet diameter of the hollow reflecting circular truncated cone is smaller than the light inlet diameter of the circular truncated cone-shaped hollow reflecting cavity, the optical waveguide bundle is arranged between the circular truncated cone-shaped hollow reflecting cavity and the inverted-pyramid-shaped hollow reflecting cavity or encapsulated in the inverted-pyramid-shaped hollow reflecting cavity, and the light inlet diameter of the inverted-pyramid-shaped hollow reflecting cavity is larger than the diameter of the optical waveguide bundle.

[0012] Further, the outer surface of the hollow reflecting circular truncated cone is coated with a total reflection film, and the slope of the circular truncated cone of the hollow reflecting circular truncated cone is 20-60 degrees.

[0013] Further, the inner wall of the circular truncated cone-shaped hollow reflecting cavity is coated with a total reflection film.

[0014] Further, the light inlet diameter of the hollow reflecting circular truncated cone is smaller than the diameter of the expanded collimated light, the diameter of the expanded collimated light is smaller than the light inlet diameter of the circular truncated cone-shaped hollow reflecting cavity, and the diameter of the expanded collimated light is 5-100 mm.

[0015] Further, the inner wall of the inverted-pyramid-shaped hollow reflecting cavity is coated with a total reflection film, and the light outlet of the inverted-pyramid-shaped hollow reflecting cavity is inlaid with a light homogenizing sheet.

[0016] Further, the light inlet of the inverted-pyramid-shaped hollow reflecting cavity is in a square structure, the light outlet is inlaid with a square light homogenizing sheet, and the diffusion angle of the light homogenizing sheet is 2-40 degrees.

[0017] Further, the optical waveguide bundle is formed by bundling a plurality of optical waveguides, the diameter of each optical waveguide is 1-10 mm, the length of each optical waveguide is 10-500 mm, and the diameter of the optical waveguide bundle is larger than the diameter of the expanded collimated light.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] The application discloses a light homogenizing and speckle eliminating system using an optical waveguide and an inverted-pyramid-shaped reflecting cavity, which comprises a hollow reflecting circular truncated cone, a circular truncated cone-shaped hollow reflecting cavity, an optical waveguide bundle, an inverted-pyramid-shaped hollow reflecting cavity and a light homogenizing sheet, wherein the circular truncated cone-shaped hollow reflecting cavity, the inverted-pyramid-shaped hollow reflecting cavity and the light homogenizing sheet are sequentially arranged along the light incidence direction, the hollow reflecting circular truncated cone is arranged at the light inlet of the circular truncated cone-shaped hollow reflecting cavity, the light inlet diameter of the hollow reflecting circular truncated cone is smaller than the light inlet diameter of the circular truncated cone-shaped hollow reflecting cavity, the optical waveguide bundle is arranged between the circular truncated cone-shaped hollow reflecting cavity and the inverted-pyramid-shaped hollow reflecting cavity or encapsulated in the inverted-pyramid-shaped hollow reflecting cavity, and the light inlet diameter of the inverted-pyramid-shaped hollow reflecting cavity is larger than the diameter of the optical waveguide bundle. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a structural schematic diagram of the application embodiment 1;

[0021] Figure 2 FIG. 2 is a structural schematic diagram of the hollow reflecting circular truncated cone of the application embodiment 1;

[0022] Figure 3 FIG. 3 is a structural schematic diagram of the circular truncated cone-shaped hollow reflecting cavity of the application embodiment 1;

[0023] Figure 4 FIG. 4 is a structural schematic diagram of the optical waveguide bundle of the application embodiment 1;

[0024] Figure 5 FIG. 5 is a structural schematic diagram of the inverted-pyramid-shaped hollow reflecting cavity of the application embodiment 1;

[0025] Figure 6 FIG. 6 is a structural schematic diagram of the application embodiment 2. DETAILED DESCRIPTION

[0026] The application will be described in detail below so that the advantages and features of the application can be more easily understood by those skilled in the art, and the protection scope of the application can be more clearly defined.

[0027] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0028] As shown in Figures 1-6 A uniform light dissipation spot system using optical waveguide and inverted pyramid type reflecting cavity, comprising coaxially arranged hollow reflecting circular cone 1, circular cone type hollow reflecting cavity 2, optical waveguide bundle 3, inverted pyramid type hollow reflecting cavity 4 and uniform light sheet 5, the circular cone type hollow reflecting cavity 2, the inverted pyramid type hollow reflecting cavity 4 and the uniform light sheet 5 are sequentially arranged along the light incidence direction, the hollow reflecting circular cone 1 is arranged at the light entrance of the circular cone type hollow reflecting cavity 2, the light entrance diameter of the hollow reflecting circular cone 1 is smaller than that of the circular cone type hollow reflecting cavity 2, the optical waveguide bundle 3 is arranged between the circular cone type hollow reflecting cavity 2 and the inverted pyramid type hollow reflecting cavity 4 or encapsulated in the inverted pyramid type hollow reflecting cavity 4, the outer surface of the hollow reflecting circular cone 1 is coated with a total reflection film, the circular cone slope (the angle between the slope and the horizontal axis) of the hollow reflecting circular cone 1 is 20°-60°, the circular cone slope of the circular cone type hollow reflecting cavity 2 should be smaller than that of the hollow reflecting circular cone 1 to ensure that the reflected light can enter the optical waveguide bundle 3, the inner wall of the circular cone type hollow reflecting cavity 2 is coated with a total reflection film, the optical waveguide bundle 3 is bundled by multiple optical waveguides, which is a large-aperture optical waveguide bundle, thereby reducing the spatial coherence of the laser, the inner wall of the inverted pyramid type hollow reflecting cavity 4 is coated with a total reflection film, the light entrance of the inverted pyramid type hollow reflecting cavity 4 is in a square structure, the light entrance diameter should be larger than the diameter of the optical waveguide bundle 3, the light exit is inlaid with a square uniform light sheet 5, and the diffusion angle of the uniform light sheet 5 is 2°-40°. The uniform light dissipation spot system adopts a coaxial structure scheme and can be used for uniform light dissipation spot of a large-aperture collimated light beam, and does not use a vibration structure, so the system will not produce any vibration.

[0029] If the optical waveguide bundle 3 is arranged between the circular cone type hollow reflecting cavity 2 and the inverted pyramid type hollow reflecting cavity 4, the optical waveguide bundle 3 is bundled by multiple optical waveguides, the diameter of each optical waveguide is 1-10 mm, and the length is 10-500 mm, the diameter of the optical waveguide bundle 3 should be larger than the diameter of the expanded collimated light, and the optical waveguide is bundled in a cylindrical hollow sleeve, Figure 4As shown, the refractive index of the filling material needs to be less than that of the optical waveguide material to achieve total reflection condition, the gap between the optical waveguides is as small as possible to better scatter the light beam, and the cylindrical hollow sleeve can be made of ceramic material to play a role of heat dissipation. The optical waveguide is preferably made of silica material with a refractive index of 1.5. Since the optical waveguide is not completely smooth, the light will continuously scatter and reflect when transmitting in the optical waveguide, thereby reducing the coherence of the light beam to suppress speckle and play a role of light homogenization.

[0030] If the optical waveguide bundle 3 is directly packaged in the inverted pyramid hollow reflective cavity 4, the optical waveguide bundle 3 is bundled by a plurality of optical waveguides, each optical waveguide has a diameter of 1-10 mm and a length of 10-500 mm, the diameter of the optical waveguide bundle 3 should be greater than that of the expanded beam collimation light, and the optical waveguide bundle 3 is not provided with a cylindrical hollow sleeve outside, and the gap and the edge are not provided with filling materials, and the same effect of light homogenization and speckle suppression can be achieved, as shown in Figure 6

[0031] The inverted pyramid hollow reflective cavity 4 is designed in an inverted pyramid structure, which can increase the reflection times of the light beam and change the reflection angle of the light beam to form light rays with different reflection angles, thereby reducing the spatial coherence of the light beam to further suppress speckle. The light outlet and the light homogenization sheet are made in an integrated structure to achieve better illumination uniformity.

[0032] Any medium that can propagate a light beam can be regarded as an optical waveguide, such as optical fiber, silica waveguide, optical plastic waveguide and any other material medium.

[0033] The working principle of the present application is as follows:

[0034] ​A bundle of expanded collimated light first enters the hollow reflective circular truncated cone 1, the aperture of the expanded collimated light is 5-100mm, the light entrance aperture of the hollow reflective circular truncated cone 1 needs to be less than the aperture of the expanded collimated light, and the aperture of the expanded collimated light needs to be less than the light entrance aperture of the circular truncated cone type hollow reflective cavity 2. Part of the light of the expanded collimated light successively passes through the circular truncated cone hole of the hollow reflective circular truncated cone 1 and the circular truncated cone hole of the circular truncated cone type hollow reflective cavity 2 and is horizontally injected into the light waveguide bundle 3, and the other part of the light is injected onto the outer surface of the hollow reflective circular truncated cone 1 coated with a total reflection film. This part of the light is reflected on the outer surface of the hollow reflective circular truncated cone 1 with a truncated cone slope, and the reflected light is injected into the circular truncated cone type hollow reflective cavity 2 with a larger aperture. The inner wall of the circular truncated cone type hollow reflective cavity 2 is coated with a total reflection film, thereby reducing the optical power loss. The reflected light is reflected twice in the circular truncated cone type hollow reflective cavity 2, and the twice-reflected light will have a certain angle with the horizontal optical axis. These light rays with a certain angle are injected into the light waveguide bundle 3 again, thereby reducing the spatial coherence of the light beam to achieve the purpose of suppressing speckle. The light injected into the light waveguide bundle 3 will be reflected and scattered in the waveguide to further suppress speckle noise and achieve the effect of light homogenization. The light beam emitted from the light waveguide bundle 3 is injected into the inverted pyramid type hollow reflective cavity 4, the processed light beam is injected into the light homogenization sheet 5 inlaid in the light outlet to achieve secondary light homogenization, and finally the processed light beam is emitted from the light outlet.

[0035] Example 1

[0036] As Figures 1-5As shown in the figure, a uniform light dissipation spot system using optical waveguide and inverted pyramid type reflecting cavity comprises coaxially arranged hollow reflecting circular cone 1, circular cone type hollow reflecting cavity 2, optical waveguide bundle 3, inverted pyramid type hollow reflecting cavity 4 and uniform light sheet 5, the circular cone type hollow reflecting cavity 2, the inverted pyramid type hollow reflecting cavity 4 and the uniform light sheet 5 are sequentially arranged along the light incidence direction, the hollow reflecting circular cone 1 is arranged at the light inlet of the circular cone type hollow reflecting cavity 2, the light inlet diameter of the hollow reflecting circular cone 1 is smaller than the light inlet diameter of the circular cone type hollow reflecting cavity 2, the optical waveguide bundle 3 is arranged between the circular cone type hollow reflecting cavity 2 and the inverted pyramid type hollow reflecting cavity 4, the outer surface of the hollow reflecting circular cone 1 is coated with total reflection film, the circular cone slope (the angle between the slope and the horizontal axis) of the hollow reflecting circular cone 1 is 20°-60°, the circular cone slope of the circular cone type hollow reflecting cavity 2 should be smaller than that of the hollow reflecting circular cone 1, so as to ensure that the reflected light can be shot into the optical waveguide bundle 3, the inner wall of the circular cone type hollow reflecting cavity 2 is coated with total reflection film, the optical waveguide bundle 3 is bundled by a plurality of optical waveguides, which is a large-diameter optical waveguide bundle, so as to reduce the spatial coherence of the laser, the inner wall of the inverted pyramid type hollow reflecting cavity 4 is coated with total reflection film, the light inlet of the inverted pyramid type hollow reflecting cavity 4 is in square structure, the light inlet diameter should be larger than the diameter of the optical waveguide bundle 3, the light outlet is inlaid with a square uniform light sheet 5, and the diffusion angle of the uniform light sheet 5 is 2°-40°. The uniform light dissipation spot system adopts a coaxial structure scheme, can be used for uniform light dissipation spot of a large-diameter collimated light beam, and does not adopt a vibration structure, so that the system will not produce any vibration.

[0037] The optical waveguide bundle 3 is bundled by a plurality of optical waveguides, the diameter of each optical waveguide is 1-10 mm, and the length is 10-500 mm, the diameter of the optical waveguide bundle 3 should be larger than the diameter of the expanded collimated light, the optical waveguide is bundled in a cylindrical hollow sleeve, as shown in the figure, Figure 4 The refractive index of the filling material needs to be smaller than the refractive index of the optical waveguide material to achieve total reflection, the gap between the optical waveguides is as small as possible so as to better scatter the light beam, and the cylindrical hollow sleeve can use ceramic material to play a role of heat dissipation. The optical waveguide is preferably made of silica material, and the refractive index is 1.5. Since the optical waveguide is not completely smooth, the light will continuously scatter and reflect when transmitting in the optical waveguide, so as to reduce the coherence of the light beam to suppress the speckle, and the optical waveguide can also play a role of uniform light.

[0038] The inverted pyramid type hollow reflecting cavity 4 is designed into an inverted pyramid type structure, which can increase the reflection times of the light beam and change the reflection angle of the light beam to form light rays with different reflection angles, so as to reduce the spatial coherence of the light beam to further suppress the speckle, and the light outlet and the uniform light sheet are made into an integrated structure to realize better illumination uniformity.

[0039] The working principle of the present application is as follows:

[0040] A bundle of expanded collimated light first enters the hollow reflecting circular truncated cone 1, the aperture of the expanded collimated light is 5-100mm, the light entrance aperture of the hollow reflecting circular truncated cone 1 needs to be less than the aperture of the expanded collimated light, and the aperture of the expanded collimated light needs to be less than the light entrance aperture of the circular truncated cone type hollow reflecting cavity 2. Part of the light of the expanded collimated light successively passes through the circular truncated cone hole of the hollow reflecting circular truncated cone 1 and the circular truncated cone type hollow reflecting cavity 2 and is horizontally injected into the light waveguide bundle 3, and the other part of the light is injected onto the outer surface of the hollow reflecting circular truncated cone 1 coated with a total reflection film, and the reflected light is injected into the circular truncated cone type hollow reflecting cavity 2 with a larger aperture. The inner wall of the circular truncated cone type hollow reflecting cavity 2 is coated with a total reflection film, thereby reducing the light power loss, and the reflected light is reflected twice in the circular truncated cone type hollow reflecting cavity 2. The twice-reflected light will have a certain angle with the horizontal optical axis, and the light with the certain angle is injected into the light waveguide bundle 3 again, thereby reducing the spatial coherence of the light beam to achieve the purpose of suppressing speckle. The light injected into the light waveguide bundle 3 will be reflected and scattered in the waveguide to further suppress speckle noise and achieve the effect of light homogenization. The light beam emitted from the light waveguide bundle 3 is injected into the inverted pyramid type hollow reflecting cavity 4, the processed light beam is injected into the light homogenization sheet 5 inlaid in the light outlet to be homogenized again, and finally the processed light beam is emitted from the light outlet.

[0041] Embodiment 2

[0042] The difference between this embodiment and embodiment 1 is that the light waveguide bundle 3 is packaged in the inverted pyramid type hollow reflecting cavity 4, the light waveguide bundle 3 is bundled by a plurality of light waveguides, the aperture of each light waveguide is 1-10mm, and the length is 10-500mm. The aperture of the light waveguide bundle 3 should be greater than the aperture of the expanded collimated light, and the light waveguide bundle 3 is not provided with a cylindrical hollow sleeve outside, and the gap and the edge are not filled with a filling material, and the purpose of light homogenization and speckle suppression can also be achieved, as shown in Figure 6 .

[0043] The same as embodiment 1.

[0044] The parts or structures not specifically described in the present application can adopt the prior art or existing products, which will not be described here.

[0045] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the present application specification, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A uniform light dissipation speckle system using an optical waveguide and an inverted pyramid-shaped reflection cavity, characterized by, The hollow reflection cone, the hollow reflection cavity, the light waveguide bundle, the hollow reflection cavity and the light uniformity sheet are coaxially arranged. The hollow reflection cavity, the hollow reflection cavity and the light uniformity sheet are sequentially arranged along the light incidence direction, and the inner wall of the hollow reflection cavity is coated with a total reflection film. The hollow reflection cone is arranged at the light inlet of the hollow reflection cavity, and the light inlet diameter of the hollow reflection cone is smaller than that of the hollow reflection cavity. The light waveguide bundle is packaged in the hollow reflection cavity, and the light waveguide bundle is bundled by a plurality of silica light waveguides. 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