Optical element and preparation method for optical system of coordinate measuring machine

Abstract

The present invention relates to the technical field of optical element preparation, and specifically discloses an optical element for a three-coordinate measuring machine optical system and a preparation method thereof. Among them, the optical element for the three-coordinate measuring machine optical system includes: a substrate formed with fused quartz as the main body, and the surface of the substrate forms a non-smooth curved surface from the edge side towards the center of the substrate; the non-smooth curved surface is processed as the surface to have a continuous wave form formed based on convex peaks and concave valleys; a thin film layer made of Al2O3 is provided on the upper part of the non-smooth curved surface, and the thin film layer forms a smooth curved surface on the upper part of the substrate. In this application, a continuous wave form formed based on convex peaks and concave valleys is obtained on the substrate formed with fused quartz as the main body by means of etching, and the screening of light waves is achieved by controlling the width and depth between the convex peaks and the concave valleys. Compared with the traditional technology, it is easy to control to obtain continuous convex peaks and concave valleys on the substrate by means of etching.

Description

Technical Field

[0001] The invention relates to the technical field of optical element manufacturing for a three-coordinate measuring machine, and in particular to an optical element used in an optical system of a three-coordinate measuring machine and a preparation method thereof. Background Art

[0002] Traditional optical components, especially those used in the field of precision devices, require the ability to filter out light waves of specific wavelengths. Generally, when preparing the optical components, the base material (quartz glass) of the optical components to be prepared must be roughened on the surface. After the roughened quartz glass is prepared into an optical component, it can filter out a certain range of light waves. However, the current surface roughening of quartz glass is basically carried out by etching, and a specific proportion of micropores is required on the quartz glass to ensure the screening of specific light waves. Currently, no domestic manufacturer can implement this technology. Summary of the invention

[0003] In view of this, an object of the present invention is to provide an optical element for a three-dimensional coordinate measuring machine optical system and a preparation method thereof, so as to solve the problems raised in the background technology.

[0004] The main purpose of the present application is to provide an optical element for a three-dimensional coordinate measuring machine optical system, comprising:

[0005] A substrate formed with quartz glass as the main body, the surface of the substrate forms a non-smooth curved surface from the side to the center of the substrate; the non-smooth curved surface is processed as a surface to have a continuous wave shape formed based on convex peaks and concave valleys;

[0006] A thin film layer made of Al2O3 is arranged on the upper part of the non-smooth curved surface, and the thin film layer forms the upper part of the substrate into a smooth curved surface.

[0007] Furthermore, the continuous peaks and valleys on the non-smooth curved surface are obtained by etching with an etching solution and then polishing.

[0008] Furthermore, the continuous peaks and valleys on the non-smooth curved surface are obtained by etching using multiple mold components and utilizing intermittent staggered etching.

[0009] Furthermore, the inclined surface from the convex peak to the concave valley is a V-shaped arc surface, and the center width between two adjacent arc surfaces is smaller than the width between two adjacent convex peaks.

[0010] The present invention also provides a method for manufacturing an optical element for a coordinate measuring machine optical system, comprising the following steps:

[0011] 1) Using quartz glass as a substrate, the surface of the substrate is polished so that the surface of the substrate forms a smooth curved surface from the side to the center of the substrate;

[0012] 2) evenly arranged long grooves are drawn on the curved surface, and then the substrate is placed on the fixture and clamped;

[0013] 3) placing a first mold having the same curvature as the curved surface on the upper part of the substrate, wherein the surface edge of the first mold exceeds the edge of the substrate and has an outward extension section, and a plurality of evenly arranged seepage grooves are opened on the surface of the first mold, and the seepage grooves match and correspond to the long notches;

[0014] 4) The first mold is attached to the substrate and compacted, and then etching liquid is added into the seepage tank. The etching liquid enters the long slot from the seepage tank to etch the long slot;

[0015] 5) After the etching reaches the set time, the first mold is removed, and the second mold is installed in the same way as step 3), and the seepage groove of the second mold is offset from the seepage groove of the first mold, and step 4 is repeated); until the etching of the substrate is completed;

[0016] 6) Remove the substrate and perform secondary grinding to ensure that the wave shape formed by the peaks and valleys of the substrate meets the set requirements;

[0017] 7) A thin film layer made of Al2O3 is disposed on the upper portion of the curved surface.

[0018] Furthermore, the width of the long slot is 3-8 μm.

[0019] Furthermore, the width of the seepage groove is 5-100 μm; and the seepage groove is V-shaped, and the width of the bottom opening is not greater than 7 μm.

[0020] Furthermore, the first mold and the second mold have the same structure, and both have a fixing platform extending upward, and the edge of the fixing platform forms a ring seat for sealing and fixing.

[0021] Furthermore, during the etching process, a sealing cover for sealing the first mold or the second mold is installed on the upper part of the first mold or the second mold, and the sealing cover has an air inlet, and inert gas is introduced into the sealing cover to achieve pressurization during the etching process.

[0022] Furthermore, the sealing cover has a sealing platform arranged corresponding to the ring seat.

[0023] In the present application, a continuous wave form based on convex peaks and concave valleys is obtained by etching on a substrate formed with quartz glass as the main body. The thin film layer made of Al2O3 has a high transmittance. The light waves entering the wave form interface are reflected by the wave form interface. Therefore, the light waves can be screened by controlling the width and depth between the convex peaks and concave valleys forming the wave form. Compared with the traditional technology, it is easy to control the continuous convex peaks and concave valleys obtained by etching on the substrate using quartz glass as the substrate.

[0024] In the present application, in order to ensure that the width and depth of the notches formed by continuous peaks and valleys obtained by etching on the substrate using quartz glass as the substrate are controllable, the present application utilizes at least two mold assemblies and adopts an intermittent staggered etching method to achieve this. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an exemplary diagram of the substrate of the present invention during the etching process;

[0026] Figure 2 For the present invention Figure 1 A magnified view of point A;

[0027] Figure 3 The wavelength range of the light waves screened out when the width of the slot is limited to 4-6 μm and the depth of the slot is limited to 2-2.5 μm in the present invention;

[0028] Figure 4 The wavelength range of the light waves screened out when the width of the slot is limited to 6-8 μm and the depth of the slot is limited to 2-2.5 μm in the present invention;

[0029] Figure 5 The wavelength range of the light waves screened out when the width of the slot is limited to 8-10 μm and the depth of the slot is limited to 2-2.5 μm in the present invention;

[0030] List of parts and reference numerals: 1 - substrate; 11 - long slot; 2 - mold assembly; 21 - fixing table; 22 - seepage groove; 3 - sealing cover; 31 - air inlet; 32 - sealing table. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1: The main purpose of the present application is to provide an optical element for a three-dimensional coordinate measuring machine optical system, comprising: a substrate 1 formed with quartz glass as a main body, the surface of the substrate 1 forming a non-smooth curved surface from the side to the center of the substrate 1; the non-smooth curved surface is processed as a surface to have a continuous wave shape formed by peaks and valleys; a thin film layer made of Al2O3 is arranged on the upper part of the non-smooth curved surface, and the thin film layer forms a smooth curved surface on the upper part of the substrate.

[0033] In the above, the thin film layer made of Al2O3 has high transmittance and is generally used as an anti-reflection film in optical elements. Traditionally, in order to obtain high transmittance, the thickness of the film needs to be controlled. This is because the light incident on the film is reflected at the interface. Therefore, reasonable control of the thickness of the film can greatly reduce the reflection. In general, the thickness of the film can be controlled according to the wavelength of the light wave. For example, if the wavelength of the light wave is set to λ, the thickness of the film ranges from 0.3λ to 0.6λ.

[0034] In the above, the continuous peaks and valleys on the non-smooth surface are obtained by etching with an etching solution and then polishing. Furthermore, the continuous peaks and valleys on the non-smooth surface are etched by using multiple mold components and using intermittent staggered etching.

[0035] It is quite difficult to make grooves within a few microns on quartz glass and control the depth and width by traditional mechanical processing. However, it is possible to make a 3-8 μm long groove 11 on quartz glass by mechanical processing. The present application does not require the control of the groove depth and width by mechanical processing. Etching can be performed by using several mold components and adopting the intermittent staggered etching method. Specifically, a mold assembly 2 having the same curvature as the curved surface of the substrate 1 is placed on the upper part of the substrate 1, and the surface edge of the mold assembly 2 exceeds the edge of the substrate 1 and has an extension section outward, and a plurality of evenly arranged seepage grooves 22 are opened on the surface of the mold assembly 2, and the seepage grooves 22 match and correspond to the long strip notches 11; it should be noted that the matching and correspondence between the seepage grooves 22 and the long strip notches 11 here is not a one-to-one correspondence, but is set at intervals according to certain rules, the purpose of which is to make the width of the upper part of the seepage groove 22 of the mold assembly larger, such as 50-100μm, and the seepage groove 22 is V-shaped, and the width of the bottom opening is not more than 7μm, thereby reducing the manufacturing difficulty of the mold assembly. Wider seepage grooves 22 can better inject etching solution.

[0036] It should be noted that the mold assembly in the present application is made of high molecular weight polyvinyl chloride material, which has the characteristics of easy injection molding and easy processing, and can therefore be mass-produced. Moreover, the flatness and curvature of the formed mold assembly can be precisely controlled;

[0037] Among them, the position of the seepage groove 22 on the mold assembly is determined according to the position of the long groove 11 on the substrate, and the number of the mold assemblies is determined according to the width between adjacent long grooves 11 on the substrate. The etching process is performed by intermittent staggered etching until the etching of the substrate is completed.

[0038] In the above, the slope from the peak to the valley is a V-shaped arc surface, and the center width between two adjacent arc surfaces is smaller than the width between two adjacent peaks. It should be noted that the width between the two peaks is generally controlled at 4-10μm. When the mold assembly is used to control the flow direction of the etching solution, the width of the bottom opening of the mold assembly is not greater than 7μm. Under normal circumstances, it is larger than the width of the long strip notch. At this time, the etching time can be controlled to control the width and depth of the notch formed by the peaks and valleys. After the etching process is completed, secondary grinding can be performed according to actual requirements to achieve precise control of the width and depth of the notch formed by the peaks and valleys.

[0039] The mold assembly 2 (specifically, it can be regarded as the first mold or the second mold) also has a fixing platform 21 extending upward, and the edge of the fixing platform 21 forms a ring seat for sealing and fixing. During the etching process, a sealing cover 3 for sealing the mold assembly is installed on the upper part of the mold assembly 2, and the sealing cover 3 has an air inlet 31, and inert gas is introduced into the sealing cover 3 to achieve pressurization during the etching process. The sealing cover has a sealing platform 32 arranged corresponding to the ring seat.

[0040] In the present application, a continuous wave form based on convex peaks and concave valleys is obtained by etching on a substrate formed by quartz glass as the main body. The thin film layer made of Al2O3 has a high transmittance. The light waves entering the wave form interface are reflected by the wave form interface. Therefore, the light waves can be screened by controlling the width and depth between the convex peaks and concave valleys forming the wave form. Compared with the traditional technology, it is easy to control the continuous convex peaks and concave valleys obtained by etching on the substrate using quartz glass as the substrate. In the present application, in order to ensure that the width and depth of the notch formed by the continuous convex peaks and concave valleys obtained by etching on the substrate using quartz glass as the substrate are controllable, the present application uses at least two mold assemblies and adopts the method of spaced staggered etching to achieve it.

[0041] It should also be noted that, according to actual use needs, the wave form formed based on convex peaks and concave valleys eliminates the mirror reflection, and only diffuse reflection exists. Diffuse reflection can provide a larger width for the screening of light waves. After repeated experiments, reference Figure 3 , Figure 4 as well as Figure 5 When the width of the slot is limited to 4-10μm and the depth of the long slot is limited to 1-3.5μm (preferably, the depth of the slot is limited to 2-2.5μm), light waves with a wavelength between 400-450nm can be screened out, and the optical element prepared can be used within a specific wavelength range. Therefore, it can be used as a homogenizer for single-mode or multi-mode incident laser conversion.

[0042] It should also be noted that Figure 3-Figure 5 The appearance of the secondary peak wave in is due to the unevenness of the notch.

[0043] Embodiment 2: The present invention also provides a method for manufacturing an optical element for a coordinate measuring machine optical system, comprising the following steps:

[0044] 1) Using quartz glass as a substrate, the surface of the substrate is polished so that the surface of the substrate forms a smooth curved surface from the side to the center of the substrate;

[0045] 2) evenly arranged long grooves are drawn on the curved surface, and then the substrate is placed on the fixture and clamped;

[0046] 3) placing a first mold having the same curvature as the curved surface on the upper part of the substrate, wherein the surface edge of the first mold exceeds the edge of the substrate and has an outward extension section, and a plurality of evenly arranged seepage grooves are opened on the surface of the first mold, and the seepage grooves match and correspond to the long notches;

[0047] 4) The first mold is attached to the substrate and compacted, and then etching liquid is added into the seepage tank. The etching liquid enters the long slot from the seepage tank to etch the long slot;

[0048] 5) After the etching reaches the set time, the first mold is removed, and the second mold is installed in the same way as step 3), the seepage groove of the second mold is offset from the seepage groove on the second mold, and step 4 is repeated); until the etching of the entire substrate is completed;

[0049] 6) Remove the substrate and perform secondary grinding to ensure that the wave shape formed by the peaks and valleys of the substrate meets the set requirements;

[0050] 7) A thin film layer made of Al2O3 is laid on the upper part of the curved surface.

[0051] Furthermore, the width of the long slot is 3-8 μm.

[0052] Furthermore, the width of the seepage groove is 5-100 μm; and the seepage groove is V-shaped, and the width of the bottom opening is not greater than 7 μm.

[0053] It should be noted that the continuous peaks and valleys on the curved surface are obtained by etching with an etching solution and then polishing. Furthermore, the continuous peaks and valleys on the curved surface are etched by multiple mold components in an intermittent staggered etching manner.

[0054] It is quite difficult to realize grooving within a few microns on quartz glass and to control the depth and width by traditional mechanical processing. However, it is possible to draw a 3-8μm long groove on quartz glass by mechanical processing. The present application does not require the control of the groove depth and width by mechanical processing. The etching process can be performed by using several mold components and adopting the method of interval dislocation etching. Specifically, a mold component with the same curvature as the curved surface of the substrate is placed on the upper part of the substrate, and the surface edge of the mold component exceeds the edge of the substrate and has an extension section outward, and a plurality of uniformly arranged seepage grooves are opened on the surface of the mold component, and the seepage grooves match and correspond with the long grooves; it should be noted that the matching correspondence between the seepage grooves and the long grooves here is not a one-to-one correspondence, but is set at intervals according to certain rules. The purpose of this is to make the width of the upper part of the seepage groove of the mold component larger, such as 50-100μm, and the seepage groove is V-shaped, and the width of the bottom opening is not more than 7μm, thereby reducing the manufacturing difficulty of the mold component. A wider seepage groove enables better injection of etching solution.

[0055] It should be noted that the mold assembly in the present application is made of high molecular weight polyvinyl chloride material, which has the characteristics of easy injection molding and easy processing, and can therefore be mass-produced. Moreover, the flatness and curvature of the formed mold assembly can be precisely controlled.

[0056] In the above, the slope from the peak to the valley is a V-shaped arc surface, and the center width between two adjacent arc surfaces is smaller than the width between two adjacent peaks. It should be noted that the width between the two peaks is generally controlled at 4-10μm. When the mold assembly is used to control the flow direction of the etching solution, the width of the bottom opening of the mold assembly is not greater than 7μm. Under normal circumstances, it is larger than the width of the long strip notch. At this time, the etching time can be controlled to control the width and depth of the notch formed by the peaks and valleys. After the etching process is completed, secondary grinding can be performed according to actual requirements to achieve precise control of the width and depth of the notch formed by the peaks and valleys.

[0057] The first mold and the second mold have the same structure, both of which have a fixing platform extending upward, and the edge of the fixing platform forms a ring seat for sealing and fixing.

[0058] During the etching process, a sealing cover for sealing the first mold is installed on the upper part of the first mold, and the sealing cover has an air inlet. Inert gas is introduced into the sealing cover to achieve pressurization during the etching process.

[0059] During the etching process, a sealing cover for sealing the second mold is installed on the upper part of the second mold, and the sealing cover has an air inlet. Inert gas is introduced into the sealing cover to achieve pressurization during the etching process.

[0060] The sealing cover has a sealing platform which is arranged corresponding to the ring seat.

[0061] In the present application, a continuous wave form based on convex peaks and concave valleys is obtained by etching on a substrate formed with quartz glass as the main body. The thin film layer made of Al2O3 has a high transmittance. The light waves entering the wave form interface are reflected by the wave form interface. Therefore, the light waves can be screened by controlling the width and depth between the convex peaks and concave valleys forming the wave form. Compared with the traditional technology, it is easy to control the continuous convex peaks and concave valleys obtained by etching on the substrate using quartz glass as the substrate.

[0062] In the present application, in order to ensure that the width and depth of the notches formed by continuous peaks and valleys obtained by etching on the substrate using quartz glass as the substrate are controllable, the present application utilizes at least two mold assemblies and adopts an intermittent staggered etching method to achieve this.

[0063] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for manufacturing an optical element for a coordinate measuring machine optical system, characterized in that: include: A substrate formed with quartz glass as the main body, the surface of the substrate forms a non-smooth curved surface from the side to the center of the substrate; the non-smooth curved surface is processed as a surface to have a continuous wave shape formed based on convex peaks and concave valleys; A thin film layer made of Al2O3 is arranged on the upper part of the non-smooth curved surface, and the thin film layer forms the upper part of the substrate into a smooth curved surface; The method for manufacturing an optical element for a three-dimensional coordinate measuring machine optical system comprises the following steps: 1) Using quartz glass as a substrate, the surface of the substrate is polished so that the surface of the substrate forms a smooth curved surface from the side to the center of the substrate; 2) evenly arranged long grooves are drawn on the curved surface, and then the substrate is placed on the fixture and clamped; 3) placing a first mold having the same curvature as the curved surface on the upper part of the substrate, wherein the surface edge of the first mold exceeds the edge of the substrate and has an outward extension section, and a plurality of evenly arranged seepage grooves are opened on the surface of the first mold, and the seepage grooves match and correspond to the long notches; 4) The first mold is attached to the substrate and compacted, and then etching liquid is added into the seepage tank. The etching liquid enters the long slot from the seepage tank to etch the long slot; 5) After the etching reaches the set time, the first mold is removed, and the second mold is installed in the same way as step 3), and the seepage groove of the second mold is offset from the seepage groove of the first mold, and step 4 is repeated); until the etching of the substrate is completed; 6) Remove the substrate and perform secondary grinding to ensure that the wave shape formed by the peaks and valleys of the substrate meets the set requirements; 7) A thin film layer made of Al2O3 is disposed on the upper portion of the curved surface.

2. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 1, characterized in that: The continuous peaks and valleys on the non-smooth curved surface are obtained by etching with an etching solution and then polishing.

3. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 2, characterized in that: The continuous convex peaks and concave valleys on the non-smooth curved surface are obtained by etching using multiple mold components and utilizing intermittent staggered etching.

4. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 1, characterized in that: The inclined surface from the convex peak to the concave valley is a V-shaped arc surface, and the center width between two adjacent arc surfaces is smaller than the width between two adjacent convex peaks.

5. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 1, characterized in that: The width of the long slot is 3-8 μm.

6. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 1, characterized in that: The width of the seepage groove is 5-100 μm; and the seepage groove is V-shaped, and the width of the bottom opening is not greater than 7 μm.

7. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 1, characterized in that: The first mold and the second mold have the same structure, and both have a fixing platform extending upward, and the edge of the fixing platform forms a ring seat for sealing and fixing.

8. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 7, characterized in that: During the etching process, a sealing cover for sealing the first mold or the second mold is installed on the upper part of the first mold or the second mold, and the sealing cover has an air inlet. Inert gas is introduced into the sealing cover to achieve pressurization during the etching process.

9. The method for manufacturing an optical element for a coordinate measuring machine optical system according to claim 8, characterized in that: The sealing cover has a sealing platform arranged corresponding to the ring seat.

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