High-precision polishing method and device for grating prism surface shape

Abstract

The application discloses a kind of high-precision polishing processing method and device of grating prism surface shape, wherein, polishing processing method includes: rough product processing step;Side polishing step;Inclined surface polishing step;First optical surface polishing step: the first side or second side of polishing completion is fixed in second processing body with photoresist, again, the first processing surface photoresist of several second processing bodies is fixed in a photoresist plate, using ring polishing machine with polishing powder as polishing medium, control pressure is 0.9-1.1kg, speed is 1.8-2.1rpm, and polishing treatment is carried out until smoothness and surface shape reach predetermined parameter;Second optical surface polishing step: after separating second processing body from photoresist plate, it is turned over to make its second processing surface fixed on photoresist plate, repeat the above steps;Product processing step.The application can guarantee that grating prism surface shape after lower disc is uniform and reaches requirement, and avoids the phenomenon of producing line in polishing process, and makes the roughness after polishing processing can reach 1nm level.

Description

Technical Field

[0001] This invention relates to the field of optical component processing technology, and in particular to a method and apparatus for high-precision polishing of grating prism surfaces. Background Technology

[0002] Grating prisms are mainly used in wavelength selective switches (WSS) in the field of optical communication. They mainly play the role of diffraction and beam splitting, so the surface accuracy and uniformity of the product are required to be high (PV<0.25λ and uniform high surface).

[0003] like Figure 1 As shown, currently, grating prism products generally use a long strip-shaped body 10 to process the angle and polished surface of the long strip-shaped product 20, and then... Figure 2 As shown, the long strip product 20 is cut into finished products 30 that meet the specified dimensions. Because the grating prism products are relatively large, generally 30-40mm in length, and use high-density glass (ρ=3.55) as the processing material, the overall weight is quite large, usually exceeding 3.5Kg. Therefore, after the above-mentioned processing, the edge shape of the finished product is prone to significant changes, failing to meet the required surface shape. Furthermore, this type of glass material has a hardness of HK550, which is relatively soft and easily produces streaks during polishing. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high-precision polishing method and apparatus for grating prism surface shape, which has the advantages of simple operation, low cost and high yield.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] According to a first aspect of the present disclosure, a method for high-precision polishing of a grating prism surface is provided, comprising:

[0007] Rough product processing steps: Take the glass raw material and cut it into predetermined specifications to obtain the rough product. Each side of the rough product has reserved processing dimensions.

[0008] Side polishing steps: First, fix the second side to a fixed plate. Then, perform rough grinding and fine grinding on the first side to achieve the predetermined surface roughness. Next, use polyurethane and polishing powder as polishing media to polish until the smoothness and surface shape reach the predetermined parameters, thus completing the polishing process of the first side. Then, fix the first side to the fixed plate and repeat the above steps to polish the second side.

[0009] Bevel polishing steps: Fix the polished first or second side to the first processing body with an upper angle of 90°, and perform rough grinding and fine grinding in sequence to achieve the predetermined surface roughness. Then, use polyurethane and polishing powder as polishing media to polish until the smoothness reaches the predetermined parameters.

[0010] First optical surface polishing step: Fix the polished first or second side surface adhesive to the second processing support, then fix the first processing surface adhesive of several second processing supports to a adhesive plate, keeping the direction and height consistent, and perform rough grinding and fine grinding in sequence to achieve the predetermined surface roughness. Then use a ring polisher with polishing powder as the polishing medium, control the pressure to be 0.9-1.1 kg and the rotation speed to be 1.8-2.1 rpm to polish until the smoothness and surface shape reach the predetermined parameters.

[0011] The second optical surface polishing step: After separating the second processing body from the optical adhesive plate, flip it over so that its second processing surface is fixed on the optical adhesive plate. After coarse grinding and fine grinding are performed in sequence to achieve the predetermined surface roughness, use a ring polisher with polishing powder as the polishing medium, control the pressure to be 0.9-1.1 kg and the rotation speed to be 1.8-2.1 rpm to polish until the smoothness and surface shape reach the predetermined parameters.

[0012] Finished product processing steps: Separate the polished finished product from the second processing body, and then clean and inspect it.

[0013] To achieve the above technical solution, sufficient processing dimensions are reserved during the roughing process to facilitate subsequent processing steps. Utilizing the principle that the side-fixed lower plate is not easily deformed, the side-fixed upper plate is used for processing during side polishing, bevel polishing, first optical surface polishing, and second optical surface polishing. This ensures that the grating prism surface shape after the lower plate is uniform and meets the requirements. At the same time, a ring polishing machine is used for polishing, and reasonable pressure and speed are controlled to avoid the formation of textures during polishing and to achieve a roughness of 1nm after polishing.

[0014] In some exemplary embodiments, the processing size is 0.3 to 0.8 mm.

[0015] In some exemplary embodiments, in the side polishing step, the fixing plate is a K9 glass polishing plate, which is rough ground to a remaining processing size of 0.1 to 0.15 mm, and fine ground to a surface roughness of 0.1 to 0.3 μm, a smoothness of 40-20, and a surface shape of <λ / 4@632.8 nm.

[0016] In some exemplary embodiments, in the bevel polishing step, rough grinding is performed until the remaining processing size is 0.1 to 0.15 mm, and fine grinding is performed until the surface roughness is 0.1 to 0.3 μm and the surface finish is 60-40.

[0017] In some exemplary embodiments, in both the first and second optical surface polishing steps, the surface roughness is controlled to be 0.1-0.3 μm, the smoothness is 20-10, and the surface shape is <λ / 8@632.8 nm.

[0018] In some exemplary embodiments, W28 diamond abrasive is used for coarse grinding and W10 diamond abrasive is used for fine grinding.

[0019] In some exemplary embodiments, the polishing powder used is 2800 polishing powder or 2885 polishing powder, which is used to prepare a polishing liquid as a polishing medium, with a specific gravity of 1.015 and a pH of 7 to 8.

[0020] According to a second aspect of the present disclosure, a high-precision polishing apparatus for grating prism surfaces is provided, for performing the polishing method as described in the first aspect, including:

[0021] A ring polisher is used for polishing processes;

[0022] A storage tank for holding polishing media, the storage tank being equipped with a stirring device for agitating the polishing media; and,

[0023] A peristaltic pump is used to pump polishing media to the polishing section of a ring polisher.

[0024] To achieve the above technical solution, the polishing medium is usually a polishing liquid containing polishing powder. During the polishing process, the polishing powder is prone to sedimentation, resulting in uneven specific gravity of the polishing liquid. The polishing medium is circulated and stirred by a stirring device to make the overall uniformity of the polishing medium higher. Then, the polishing liquid is pumped from the storage tank to the polishing part of the ring polisher by a peristaltic pump, thereby realizing the polishing process of the prism and realizing automatic and uniform liquid addition during the polishing process, which improves the smoothness of the prism and reduces the generation of polishing marks.

[0025] In some exemplary embodiments, the stirring device includes: a stirring motor fixed to the top of the storage tank, a stirring shaft fixed to the stirring motor, and a plurality of stirring paddles fixed to the stirring shaft.

[0026] To achieve the above technical solution, a stirring motor drives the stirring shaft to rotate, which in turn drives the stirring paddle to stir the polishing medium, making the polishing medium more uniform.

[0027] In some exemplary embodiments, the peristaltic pump is connected to a supply pipe that extends into the tank and near the bottom of the tank, and the supply pipe is secured to the tank by several clips.

[0028] To achieve the above technical solution, the liquid supply pipe is fixed to the inner wall of the storage tank by several clips, so as to avoid the liquid supply pipe shaking or interfering or tangling with the stirring paddle due to disturbance of the polishing medium during the stirring process.

[0029] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention provides a high-precision polishing method and apparatus for grating prism surfaces. When forming the rough finished product, sufficient processing dimensions are reserved for subsequent processing steps. Utilizing the principle that the side-fixed lower plate is not easily deformed, the side-fixed upper plate is used for side polishing, bevel polishing, first optical surface polishing, and second optical surface polishing. This ensures that the grating prism surface after the lower plate is fixed is uniform and meets requirements. Simultaneously, a ring polisher is used for polishing, and reasonable pressure and rotation speed are controlled to avoid texture formation during polishing, achieving a surface roughness of 1nm after polishing. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the existing upper plate processing in the background art.

[0032] Figure 2 This is a schematic diagram of existing cutting processes in the background art.

[0033] Figure 3 The image shows the polished finish of a product processed using existing technology, where visible textures are clearly visible.

[0034] Figure 4 This is a schematic diagram of the assembly structure in the first optical surface polishing step of the present invention.

[0035] Figure 5 This is a schematic diagram of the assembly structure in the second optical surface polishing step of the present invention.

[0036] Figure 6 This is a polishing effect diagram of the grating prism prepared by the polishing method of the present invention.

[0037] Figure 7 The image shows the roughness test results of the grating prism prepared by the polishing method of this invention.

[0038] Figure 8 This is a schematic diagram of the polishing apparatus of the present invention.

[0039] The numbers and letters in the diagram represent the names of the corresponding components:

[0040] 10. Support body; 20. Product; 30. Finished product; 40. Prism to be processed; 50. Second processing support body; 60. Glossy sheet; 70. Ring polishing machine; 80. Storage tank; 81. Stirring device; 82. Stirring motor; 83. Stirring shaft; 84. Stirring paddle; 90. Peristaltic pump; 91. Liquid supply pipe; 92. Buckle. Detailed Implementation

[0041] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] like Figures 1 to 7 As shown, the first aspect of this invention provides a high-precision polishing method for grating prism surfaces, comprising:

[0043] S100. Rough Finished Product Processing Steps: Take the glass raw material and cut it into predetermined specifications to obtain the rough finished product. Each side of the rough finished product has a reserved processing size, which is 0.3 to 0.8 mm. Preferably, the reserved processing size is set to 0.5 mm. The glass raw material can be of model SCHOTT N-SK2 and is cut into predetermined specifications using a J5060 internal circle cutting machine.

[0044] S200, Side Polishing Steps: First, fix the second side to a fixed plate. Then, perform rough grinding and fine grinding on the first side in sequence to achieve the predetermined surface roughness. Next, use polyurethane and polishing powder as polishing media to polish until the smoothness and surface shape reach the predetermined parameters, thus completing the polishing process of the first side. Then, fix the first side to the fixed plate and repeat the above steps to polish the second side.

[0045] Specifically, the fixing plate is a K9 glass adhesive plate. The second side can be glued to the fixing plate with quick-drying adhesive or fixed to the fixing plate with adhesive. W28 diamond abrasive is used for rough grinding until the remaining processing size is 0.1-0.15mm. Then W10 diamond abrasive is used for fine grinding until the surface roughness is 0.1-0.3μm. Preferably, when the reserved processing size is 0.5mm, rough grinding is performed on 0.4mm first, and then fine grinding is performed on 0.1mm. During polishing, polyurethane of model LP66 and 2800 polishing powder are used. The polishing powder is used to prepare a polishing liquid as a polishing medium. The specific gravity of the polishing powder is 1.015, the pH is 7-8, and the smoothness after polishing is controlled to be 40-20, and the surface shape is <λ / 4@632.8nm.

[0046] S300, Bevel Polishing Steps: (See below) Figure 4As shown, the polished first or second side is fixed to the first processing body at an angle of 90°. After rough grinding and fine grinding are performed in sequence to achieve the predetermined surface roughness, polyurethane and polishing powder are used as polishing media to polish until the surface finish reaches the predetermined parameters.

[0047] Specifically, the first processing support is a K9 glass support, and either the first or second side can be fixed to the first processing support with adhesive. W28 diamond abrasive is used for rough grinding until the remaining processing size is 0.1-0.15mm. Then W10 diamond abrasive is used for fine grinding until the surface roughness is 0.1-0.3μm. Preferably, when the reserved processing size is 0.5mm, rough grinding is performed on 0.4mm first, and then fine grinding is performed on 0.1mm. During polishing, polyurethane of model LP66 and 2800 polishing powder are used. The polishing powder is used to prepare a polishing liquid as a polishing medium. The specific gravity of the polishing powder is 1.015, the pH is 7-8, and the smoothness after polishing is controlled to be 60-40. Since the inclined surface is not used as an optical surface, no special requirements are made for the surface shape.

[0048] S400, First optical surface polishing step: as follows Figure 5 As shown, the polished first or second side surface is fixed to the second processing support body with polished adhesive. Then, several first processing surfaces of the second processing support body are fixed to a polished adhesive plate, keeping the direction and height consistent. After coarse grinding and fine grinding are performed in sequence to achieve the predetermined surface roughness, a ring polisher is used with polishing powder as the polishing medium, and the pressure is controlled at 0.9-1.1 kg and the rotation speed is controlled at 1.8-2.1 rpm to polish until the smoothness and surface shape reach the predetermined parameters. Preferably, the pressure is controlled at 1 kg and the rotation speed is controlled at 2 rpm.

[0049] Specifically, the second processing support adopts a K9 glass support, and either the first or second side can be fixed to the second processing support with adhesive. W28 diamond abrasive is used for rough grinding until the remaining processing size is 0.1-0.15mm. Then, W10 diamond abrasive is used for fine grinding until the surface roughness is 0.1-0.3μm. Preferably, when the reserved processing size is 0.5mm, rough grinding is performed first to 0.4mm, and then fine grinding is performed to 0.1mm. During polishing, polyurethane of model LP66 and 2885 polishing powder are used. The polishing powder is used to prepare a polishing liquid as a polishing medium. The specific gravity of the polishing powder is 1.015, the pH is 7-8, and the smoothness after polishing is controlled to be 20-10, and the surface shape is <λ / 8@632.8nm.

[0050] S500, Second optical surface polishing step: After separating the second processing body from the optical adhesive plate, flip it over so that its second processing surface is fixed on the optical adhesive plate. After coarse grinding and fine grinding are performed in sequence to achieve the predetermined surface roughness, use a ring polisher with polishing powder as the polishing medium, control the pressure to be 0.9~1.1kg and the rotation speed to be 1.8~2.1rpm to polish until the smoothness and surface shape reach the predetermined parameters.

[0051] Specifically, after the first optical surface is polished, the second processing body is rotated 90 degrees to expose the second optical surface. W28 diamond abrasive is used for rough grinding until the remaining processing dimension is 0.1–0.15 mm. Then, W10 diamond abrasive is used for fine grinding until the surface roughness is 0.1–0.3 μm. Preferably, when the reserved processing dimension is 0.5 mm, rough grinding is performed first to 0.4 mm, followed by fine grinding to 0.1 mm. During polishing, LP66 polyurethane and 2885 polishing powder are used. This polishing powder is used to prepare a polishing liquid as the polishing medium. The specific gravity of the polishing powder is 1.015, the pH is 7–8, and the surface finish after polishing is controlled to be 20–10, with a surface shape <λ / 8@632.8 nm.

[0052] S600 Finished product processing steps: Separate the polished finished product from the second processing body, and clean and inspect it.

[0053] When forming the rough finished product, sufficient processing dimensions are reserved for subsequent processing steps. Taking advantage of the principle that the side-fixed lower plate is not easily deformed, the side-fixed upper plate is used for processing during side polishing, bevel polishing, first optical surface polishing, and second optical surface polishing. This ensures that the grating prism surface shape after the lower plate is uniform and meets the requirements. At the same time, a ring polishing machine is used for polishing, and reasonable pressure and speed are controlled to avoid the formation of textures during polishing and to achieve a roughness of 1nm after polishing.

[0054] Process validation is performed by processing a series of samples, such as Figure 6 As shown, select one sample and observe its polishing effect. It can be seen that there are no obvious lines, as... Figure 7 As shown, the roughness of the selected sample was tested, and it can be seen that the surface roughness can be controlled within 0.1 to 0.3 μm.

[0055] The performance parameters of the first optical surface of each sample were tested, and the results are shown in the table below:

[0056] sample PV(λ) IRR: B(λ) Power(λ) RMS(λ) 1 0.113 0.108 0.046 0.075 2 0.062 0.043 0.020 0.029 3 0.091 0.070 0.046 0.049 4 0.102 0.080 0.052 0.024 5 0.118 0.081 0.065 0.048 6 0.141 0.135 0.058 0.040 7 0.134 0.120 0.045 0.017 8 0.066 0.041 0.034 0.020 9 0.117 0.119 0.012 0.032 10 0.117 0.102 0.045 0.062 11 0.153 0.084 0.068 0.053 12 0.109 0.083 0.040 0.060 13 0.090 0.102 0.003 0.039

[0057] The performance parameters of the second optical surface of each sample were tested, and the results are shown in the table below:

[0058]

[0059]

[0060] As can be seen, the grating prisms processed by the above polishing method can fully meet the surface shape requirements, effectively avoid the generation of textures, and have a high yield rate.

[0061] A second aspect of the present invention provides a high-precision polishing apparatus for grating prism surfaces, used to perform the polishing method of the first aspect, comprising: a ring polisher 70 for polishing; a storage tank 80 for holding polishing media, the storage tank 80 being provided with a stirring device 81 for stirring the polishing media; and a peristaltic pump 90 for pumping the polishing media to the polishing section of the ring polisher 70.

[0062] The stirring device 81 includes: a stirring motor 82 fixed to the top of the storage tank 80, a stirring shaft 83 fixed to the stirring motor 82, and several stirring paddles 84 fixed to the stirring shaft 83. A fixed frame is set on the top of the storage tank 80, the stirring motor 82 is fixed on the fixed frame, the stirring shaft 83 extends to the bottom of the storage tank 80, and a bearing seat is set at the bottom of the storage tank 80 to achieve rotatable connection with the stirring shaft 83. Two to three sets of stirring paddles 84 can be set along the axial direction of the stirring shaft 83. The form of the stirring shaft 83 is not limited. The stirring motor 82 drives the stirring shaft 83 to rotate, which drives the stirring paddles 84 to rotate and stir the polishing medium, making the polishing medium more uniform.

[0063] The peristaltic pump 90 is connected to a liquid supply pipe 91, which extends into the storage tank 80 and is close to the bottom of the storage tank 80. The liquid supply pipe 91 is fixed inside the storage tank 80 by several clips 92. The clips 92 can be fixed to the inner wall of the storage tank 80 by screws. The liquid supply pipe 91 is fixed to the inner wall of the storage tank 80 by several clips 92 to avoid disturbing the polishing medium during the stirring process, which would cause the liquid supply pipe 91 to shake or interfere with or become entangled with the stirring paddle 84. Of course, in some embodiments, the clips 92 may not be provided, as long as there is sufficient distance between the stirring paddle 84 and the inner wall of the storage tank 80 to avoid interference with the liquid supply pipe 91.

[0064] The polishing medium is usually a polishing slurry containing polishing powder. During the polishing process, the polishing powder tends to settle, resulting in uneven specific gravity of the polishing slurry. The polishing medium is circulated and stirred by the stirring device 81 to make the overall uniformity of the polishing medium higher. Then, the polishing slurry is pumped from the storage tank 80 to the polishing part of the ring polisher 70 by the peristaltic pump 90, thereby realizing the polishing process of the prism and realizing automatic and uniform liquid addition during the polishing process, which improves the smoothness of the prism and reduces the occurrence of polishing marks.

[0065] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A method for high-precision polishing of grating prism surfaces, characterized in that, include: Rough product processing steps: Take the glass raw material and cut it into predetermined specifications to obtain the rough product. Each side of the rough product has reserved processing dimensions. Side polishing steps: First, fix the second side to a fixed plate. Then, perform rough grinding and fine grinding on the first side to achieve the predetermined surface roughness. Next, use polyurethane and polishing powder as polishing media to polish until the smoothness and surface shape reach the predetermined parameters, thus completing the polishing process of the first side. Then, fix the first side to the fixed plate and repeat the above steps to polish the second side. Bevel polishing steps: Fix the polished first or second side to the first processing body with an upper angle of 90°, and perform rough grinding and fine grinding in sequence to achieve the predetermined surface roughness. Then, use polyurethane and polishing powder as polishing media to polish until the smoothness reaches the predetermined parameters. First optical surface polishing step: Fix the polished first or second side surface adhesive to the second processing support, then fix the first processing surface adhesive of several second processing supports to a adhesive plate, keeping the direction and height consistent, and perform rough grinding and fine grinding in sequence to achieve the predetermined surface roughness. Then use a ring polisher with polishing powder as the polishing medium, control the pressure to be 0.9-1.1 kg and the rotation speed to be 1.8-2.1 rpm to polish until the smoothness and surface shape reach the predetermined parameters. The second optical surface polishing step: After separating the second processing body from the optical adhesive plate, flip it over so that its second processing surface is fixed on the optical adhesive plate. After coarse grinding and fine grinding are performed in sequence to achieve the predetermined surface roughness, use a ring polisher with polishing powder as the polishing medium, control the pressure to be 0.9-1.1 kg and the rotation speed to be 1.8-2.1 rpm to polish until the smoothness and surface shape reach the predetermined parameters. Finished product processing steps: Separate the polished finished product from the second processing body, and then clean and inspect it.

2. The high-precision polishing method for the grating prism surface shape according to claim 1, characterized in that, The processing dimensions are 0.3 to 0.8 mm.

3. The high-precision polishing method for the grating prism surface shape according to claim 1 or 2, characterized in that, In the side polishing step, the fixing plate is a K9 glass polishing plate, which is rough ground to a remaining processing size of 0.1 to 0.15 mm, and fine ground to a surface roughness of 0.1 to 0.3 μm, a smoothness of 40-20, and a surface shape of <λ / 4@632.8 nm.

4. The high-precision polishing method for the grating prism surface shape according to claim 1 or 2, characterized in that, In the inclined surface polishing step, rough grinding is performed until the remaining processing size is 0.1 to 0.15 mm, and fine grinding is performed until the surface roughness is 0.1 to 0.3 μm and the surface finish is 60-40.

5. The high-precision polishing method for the grating prism surface shape according to claim 1 or 2, characterized in that, In both the first and second optical surface polishing steps, the surface is controlled to have a roughness of 0.1–0.3 μm, a smoothness of 20–10, and a surface shape of <λ / 8@632.8 nm.

6. The high-precision polishing method for the grating prism surface shape according to claim 1, characterized in that, W28 diamond abrasive is used for rough grinding, and W10 diamond abrasive is used for fine grinding.

7. The high-precision polishing method for the grating prism surface shape according to claim 1, characterized in that, The polishing powder used is either 2800 polishing powder or 2885 polishing powder. The polishing powder is used to prepare a polishing liquid as a polishing medium. Its specific gravity is 1.015 and its pH is 7-8.

8. A high-precision polishing device for grating prism surfaces, characterized in that, A polishing process method for performing any one of claims 1-7 includes: A ring polisher is used for polishing processes; A storage tank for holding polishing media, said storage tank being equipped with a stirring device for agitating the polishing media; and, A peristaltic pump is used to pump polishing media to the polishing section of a ring polisher.

9. The high-precision polishing apparatus for grating prism surface shape according to claim 8, characterized in that, The stirring device includes: a stirring motor fixed to the top of the storage tank, a stirring shaft fixed to the stirring motor, and several stirring paddles fixed to the stirring shaft.

10. The high-precision polishing apparatus for grating prism surfaces according to claim 8 or 9, characterized in that, The peristaltic pump is connected to a liquid supply pipe that extends into the storage tank and is close to the bottom of the tank. The liquid supply pipe is fixed inside the storage tank by several clips.

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