Testing device for measuring Wollaston prism beam separation angle
By integrating optical devices and a high-precision displacement drive motor, the problem of errors introduced by the movement of the beam analyzer was solved, and high-precision and highly repeatable beam separation angle measurement was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FUJIAN CASTECH CRYSTALS
- Filing Date
- 2025-05-20
- Publication Date
- 2026-05-01
AI Technical Summary
In the existing technology, when measuring the beam separation angle of a Wollaston prism, the error introduced by movement and poor repeatability of the beam analyzer result in low test accuracy.
An integrated laser beam generator, first and second plane mirrors, sample stage, and displacement drive motor are mounted on an optical breadboard. Combined with a large-aperture beam analyzer and a high-precision displacement drive motor, the beam collimation output and high-precision movement are achieved, ensuring that the beam analyzer can simultaneously acquire two beams and record their positions.
This improves the accuracy and repeatability of beam separation angle measurement, ensuring accurate measurement of the beam separation angle of the Wollaston prism.
Smart Images
Figure CN224189494U_ABST
Abstract
Description
A test apparatus for measuring the beam separation angle of a Wollaston prism. Technical Field
[0001] This utility model relates to the field of beam separation angle measurement technology, and in particular to a test device for measuring the beam separation angle of a Wollaston prism. Background Technology
[0002] When a beam of light enters a Wollaston prism, it splits into two polarized beams (o-ray and e-ray). Due to their different refractive indices, these two beams separate at a certain angle after passing through the prism; this angle is called the beam separation angle. The accuracy of the beam separation angle measurement depends on the position measurement of the two beams and the determination of the moving distance of the beam analyzer (beam receiver). During measurement, after the beam is refracted and transmitted through the Wollaston prism, the two beams separate at a certain angle. After a certain transmission distance, the distance between the two beams exceeds the receiving range of the beam analyzer, meaning the beam analyzer cannot simultaneously acquire both beams. Manual movement of the beam analyzer is required to acquire the beam position, but this movement introduces testing errors. Furthermore, the beam analyzer's movement distance is measured using a steel ruler, which has poor accuracy and repeatability, affecting the overall test accuracy. Summary of the Invention
[0003] The purpose of this invention is to provide a testing device for measuring the beam separation angle of a Wollaston prism, which has high moving accuracy and repeatability, ensuring accurate measurement and calculation of the beam separation angle of the Wollaston prism.
[0004] To achieve the above objectives, this utility model provides a testing device for measuring the beam separation angle of a Wollaston prism, comprising:
[0005] A laser beam generator is used to emit a laser beam.
[0006] The first planar reflector is used to reflect the laser beam emitted by the laser beam generator for the first time;
[0007] The second plane mirror is used to reflect the light beam reflected by the first plane mirror a second time.
[0008] The sample stage is used to place the Wollaston prism sample and allow the light beam reflected from the second plane mirror to enter the Wollaston prism sample.
[0009] A beam analyzer is used to receive two beams emitted from a Wollaston prism sample at a certain angle.
[0010] A displacement drive motor is used to drive the beam analyzer to move back and forth along the direction of the beam reflected by the second planar reflector.
[0011] An optical breadboard is used to fix the laser beam generator, the first planar mirror, the sample stage, and the displacement drive motor.
[0012] As a preferred embodiment of this utility model, the displacement drive motor includes a drive motor and a guide rail pair. The output end of the drive motor is connected to the beam analyzer. The guide rail of the drive motor and the guide rail pair is fixed on the optical breadboard. The beam analyzer is connected to the slider of the guide rail pair.
[0013] As a preferred embodiment of this invention, the laser beam generator is a helium-neon laser.
[0014] As a preferred embodiment of this utility model, the helium-neon laser can generate 632.8nm laser light, and the power of the helium-neon laser is 2mW.
[0015] As a preferred embodiment of this utility model, the sample stage is a five-dimensional adjustable stage.
[0016] As a preferred embodiment of this utility model, the beam analyzer is a large-aperture beam analyzer, and the effective testing area of the beam analyzer is 36mm*24mm.
[0017] As a preferred embodiment of this utility model, the movable stroke of the displacement drive motor is at least 50mm.
[0018] As a preferred embodiment of this utility model, the displacement accuracy of the displacement drive motor is 2μm.
[0019] As a preferred embodiment of this utility model, the angle between the incident beam in the first plane mirror and the reflected beam in the first plane mirror is 90°, and the angle between the incident beam in the second plane mirror and the reflected beam in the second plane mirror is 90°.
[0020] Compared with the prior art, the present invention provides a testing device for measuring the beam separation angle of a Wollaston prism, which has the following advantages:
[0021] In this invention, the laser beam generator, the first plane mirror, the sample stage, and the displacement drive motor are integrated on an optical breadboard, resulting in a complete and unified layout and improved testing accuracy. The laser beam is collimated and optimized through reflection adjustment by the first and second plane mirrors. The beam analyzer can simultaneously acquire the two beams generated by the Wollaston prism and record their positions. The beam analyzer is connected to the displacement drive motor, which drives the beam analyzer to move, achieving high-precision displacement from the initial position to the target position. This allows for accurate determination of the beam analyzer's movement distance with high accuracy and repeatability, ensuring accurate measurement and calculation of the Wollaston prism beam separation angle. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly described below.
[0023] Figure 1 is a schematic diagram of the projection calculation of the beam separation angle.
[0024] Figure 2 is a schematic diagram of the structure of a test device for measuring the beam separation angle of a Wollaston prism provided by this utility model;
[0025] Figure 3 is a schematic diagram of the structure of a test device for measuring the beam separation angle of a Wollaston prism provided by this utility model.
[0026] In the figure, there is a laser beam generator 1; a first plane mirror 2; a second plane mirror 3; a sample stage 4; a beam analyzer 5; a drive motor 61; a guide rail pair 62; and an optical breadboard 7. Detailed Implementation
[0027] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0029] As shown in Figures 2 and 3, a test apparatus for measuring the beam separation angle of a Wollaston prism according to a preferred embodiment of the present invention includes:
[0030] Laser beam generator 1, used to emit a laser beam;
[0031] The first plane mirror 2 is used to reflect the beam emitted by the laser beam generator 1 for the first time;
[0032] The second plane mirror 3 is used to reflect the light beam reflected by the first plane mirror 2 a second time.
[0033] Sample stage 4 is used to place the Wollaston prism sample and allow the light beam reflected from the second plane mirror 3 to enter the Wollaston prism sample.
[0034] Beam analyzer 5 is used to receive two beams emitted from the Wollaston prism sample at a certain angle;
[0035] The displacement drive motor 61 is used to drive the beam analyzer 5 to move back and forth along the direction of the beam reflected by the second planar reflector 3.
[0036] An optical breadboard 7 is used to fix the laser beam generator 1, the first planar mirror 2, the sample stage 4, and the displacement drive motor 61. The beam separation angle is calculated by combining geometric relationships with the distance between the beam spots of the two beams after propagating a certain distance, as shown in Figure 1. Where ΔL is the difference in separation distance between the two beams at positions 1 and 2, and d is the distance that the beam analyzer 5 moves.
[0037] In this invention, the laser beam generator 1, the first plane mirror 2, the sample stage 4, and the displacement drive motor 61 are integrated on an optical breadboard 7, resulting in a complete and unified layout and improved testing accuracy. The laser beam is collimated and optimized through reflection adjustment by the first plane mirror 2 and the second plane mirror 3. The beam analyzer 5 can simultaneously acquire the two beams generated by the Wollaston prism and record their positions. The beam analyzer 5 is connected to the displacement drive motor 61, which drives the beam analyzer 5 to move, achieving high-precision displacement from the initial position to the target position. This allows for accurate determination of the beam analyzer 5's movement distance, with high accuracy and repeatability, ensuring accurate measurement and calculation of the Wollaston prism beam separation angle.
[0038] For example, the displacement drive motor 61 includes a drive motor 61 and a guide rail pair 62. The output end of the drive motor 61 is connected to the beam analyzer 5. The guide rail of the drive motor 61 and the guide rail pair 62 is fixed on the optical breadboard 7. The beam analyzer 5 is connected to the slider of the guide rail pair 62. The stability of the beam analyzer 5 during movement is improved by setting the guide rail pair 62.
[0039] Furthermore, the laser beam generator 1 is a helium-neon laser; the helium-neon laser can generate 632.8nm laser light, and the power of the helium-neon laser is 2mW. The 632.8nm helium-neon laser has the advantages of monochromaticity and wavelength stability, which reduces the risk of error and improves the testing efficiency.
[0040] For example, the sample stage 4 is a five-dimensional adjustable stage, which can adjust the height of the Wollaston prism sample and the angle at which the laser is incident on the Wollaston prism sample.
[0041] For example, the beam analyzer 5 is a large-aperture beam analyzer 5, and the effective test area of the beam analyzer 5 is 36mm*24mm, which can effectively receive two beams.
[0042] For example, the movable stroke of the displacement drive motor 61 is at least 50mm, which meets the moving distance requirement of the beam analyzer 5. The displacement accuracy of the displacement drive motor 61 is 2μm, which improves the testing accuracy and has high repeatability.
[0043] Specifically, the angle between the incident beam in the first plane mirror 2 and the reflected beam in the first plane mirror 2 is 90°, and the angle between the incident beam in the second plane mirror 3 and the reflected beam in the second plane mirror 3 is 90°. The laser beam generator 1 and the beam analyzer 5 are both located on the same side of the first plane mirror 2 and the second plane mirror 3, making the overall structure more compact and saving space.
[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0045] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. A testing apparatus for measuring the beam separation angle of a Wollaston prism, characterized in that, include: A laser beam generator is used to emit a laser beam; a first plane mirror is used to reflect the laser beam emitted by the laser beam generator for the first time; a second plane mirror is used to reflect the laser beam reflected by the first plane mirror for the second time; a sample stage is used to place the Wollaston prism sample and to allow the laser beam reflected by the second plane mirror to enter the Wollaston prism sample; a beam analyzer is used to receive two beams emitted from the Wollaston prism sample at a certain angle. A displacement drive motor is used to drive the beam analyzer to move back and forth along the direction of the beam reflected by the second plane mirror; an optical breadboard is used to fix the laser beam generator, the first plane mirror, the sample stage and the displacement drive motor.
2. The testing apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 1, characterized in that, The displacement drive motor includes a drive motor and a guide rail pair. The output end of the drive motor is connected to the beam analyzer. The drive motor and the guide rail of the guide rail pair are fixed on the optical breadboard. The beam analyzer is connected to the slider of the guide rail pair.
3. The testing apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 1, characterized in that, The laser beam generator is a helium-neon laser.
4. The test apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 3, characterized in that, The helium-neon laser can generate 632.8nm laser light, and the power of the helium-neon laser is 2mW.
5. The test apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 1, characterized in that, The sample stage is a five-dimensional adjustable stage.
6. The testing apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 1, characterized in that, The beam analyzer is a large-aperture beam analyzer, and the effective test area of the beam analyzer is 36mm*24mm.
7. The testing apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 1, characterized in that, The displacement drive motor has a travel range of at least 50 mm.
8. The test apparatus for measuring the beam separation angle of a Wollaston prism as described in claim 7, characterized in that, The displacement accuracy of the displacement drive motor is 2μm.
9. The testing apparatus for measuring the beam separation angle of a Wollaston prism as described in any one of claims 1 to 8, characterized in that, The angle between the incident beam in the first plane mirror and the reflected beam in the first plane mirror is 90°, and the angle between the incident beam in the second plane mirror and the reflected beam in the second plane mirror is 90°.