Device for measuring 0-degree reflectivity of optical product

Abstract

The utility model discloses a device for measuring 0-degree reflectivity of an optical product, and belongs to the technical field of optical measurement. The first light path and the second light path are arranged between the light source and the two power meters, and light emitted by the light source enters the first light path and is output to the first power meter through a semi-transparent and semi-reflecting mirror; and after entering the second light path, light emitted by the light source is reflected back to the normal incidence module through the semi-transparent and semi-reflecting mirror and the normal incidence module, and the to-be-measured sample is output to the second power meter through the semi-transparent and semi-reflecting mirror. The device is suitable for measuring the 0-degree reflectivity of the optical product, the test distance of the device is short, the energy propagation loss is reduced, and the accuracy of a test result is improved.

Description

Technical Field

[0001] The utility model belongs to the field of optical measurement, and particularly relates to a device for measuring the 0° reflectivity of an optical product. Background Art

[0002] Light is an electromagnetic wave that gives us vision. The propagation of light follows certain laws, and an important one is the reflection of light. The reflection of light is a phenomenon that occurs when light rays encounter a boundary surface when traveling from one medium to another. The reflectivity of light represents the degree of energy reflection and depends on the characteristics of the object and the incident angle of the light rays. By utilizing the characteristics of reflection and reflectivity, we can design various optical devices and apply them to real life, thereby improving the quality of life and safety.

[0003] In the field of optics, reflected light is used in many applications. There are various testing methods for measuring the energy of reflected light, such as the spectrophotometer testing method, the laser direct measurement method, and the transmittance conversion method. However, when measuring the reflected energy at 0° incidence, each of these three methods has its drawbacks; when using a spectrophotometer to test reflection, the reflected light must be separated from the incident light for testing. Therefore, when testing 0° reflection, the incident light can only have an angle of about 6° to measure the reflected light. Strictly speaking, this testing method is inaccurate; the laser direct measurement method also has the same problem as the spectrophotometer measurement. To make the incident angle closer to 0°, only the testing distance between the light source and the product can be increased, but in this way, the energy loss during propagation will also increase, resulting in inaccurate test results; for the transmittance conversion method: due to the absorption and scattering of the sample, the sum of the transmittance and the reflectivity is not 100%. Using R = 1 - T to calculate the reflectivity, the obtained result is also inaccurate. Summary of the Invention

[0004] The purpose of the utility model is to provide a device for measuring the 0° reflectivity of an optical product in view of the problems existing in the prior art. The device has a small testing distance, reduces the energy propagation loss, and increases the accuracy of the test results.

[0005] To achieve the above purpose, the technical solution adopted by the utility model is: according to one aspect of the specification of the utility model, a device for measuring the 0° reflectivity of an optical product is provided, which includes a light source, two power meters, and a first optical path and a second optical path arranged between the light source and the two power meters. Among them, the light emitted by the light source enters the first optical path and is output to the first power meter via a semi-transparent and semi-reflective mirror; after the light emitted by the light source enters the second optical path, it is reflected back to the normal incidence module, semi-transparent and semi-reflective mirror via the semi-transparent and semi-reflective mirror, normal incidence module, and the sample to be measured, and then output to the second power meter.

[0006] Optionally, the light source is fixed using a light source fixing bracket, and the semi-transparent and semi-reflective mirror and the sample to be measured are fixed using a five-axis adjustment bracket, which is used to adjust the height and angle of the semi-transparent and semi-reflective mirror and the sample to be measured.

[0007] Further, the light source can emit collimated polarized light, and the polarization direction is parallel to the plane.

[0008] Further, the beam splitting ratio of the semi-transparent and semi-reflective mirror is 50 / 50, and an anti-reflection film is coated on the front surface of the semi-transparent and semi-reflective mirror, and a beam splitting film is coated on the back surface.

[0009] Optionally, the incident surface of the sample to be measured is a smooth surface, and the back surface is not polished or coated with an anti-reflection film.

[0010] Further, the normal incidence module includes a corner cube prism, a depolarizing beam splitter prism, and an autocollimator, and the beam splitting ratio of the depolarizing beam splitter prism among them is 50 / 50. By using the normal incidence module, the angle of the light reflected by the sample to be measured can be adjusted to 0°, making the device more rigorous.

[0011] Further, when the light beam reflected by the sample to be measured enters the semi-transparent and semi-reflective mirror, the included angle with the semi-transparent and semi-reflective mirror is 45°. Adjusting the included angle to 45° is beneficial to detecting the propagation path of the light through the characteristics of light refraction.

[0012] According to the above device, a method for measuring the 0° reflectivity of an optical product can be obtained: the light emitted by the light source passes through the semi-transparent and semi-reflective mirror at an incident angle of 45°, and the first power meter is used to obtain the refracted light power P1 refracted by the semi-transparent and semi-reflective mirror, and the second power meter is used to obtain the transmitted light power P2 transmitted by the semi-transparent and semi-reflective mirror.

[0013] The normal incidence module and the sample to be measured are sequentially placed on the transmitted light path, the sample to be measured is adjusted so that the light reflected by the sample to be measured passes through the corner cube prism and the depolarizing beam splitter prism and is reflected into the autocollimator with the included angle between the two beams of light <5″, and then the incident module is removed. At this time, the light is normally incident on the sample to be measured, and the power meter is used to obtain the power P3 after the reflected light of the sample to be measured is refracted by the semi-transparent and semi-reflective mirror. Assume that the power transmitted through the semi-transparent and semi-reflective mirror after the reflected light of the sample to be measured is P4.

[0014] According to the reflectivity R = reflected light power / incident light power;

[0015] The incident light power is P2, and the reflected light power is P3 + P4;

[0016] Then R = (P3 + P4) / P2;

[0017] Among them, according to the principle of energy conservation, it is obtained that: P1 / P2 = P3 / P4;

[0018] So P4 = P2 × P3 / P1;

[0019] Substituting into the formula gives the formula for the 0° reflectivity of the sample to be measured:

[0020] R = P3(P1 + P2) / (P1 × P2).

[0021] Furthermore, the incident angle of the light emitted by the light source and the semi-transparent and semi-reflective mirror can have a deviation of ±2°. Due to the principle of energy conservation, the deviation of ±2° has little impact on this experiment.

[0022] Furthermore, in the normal incidence module, the corner cube prism and the depolarizing beam splitter prism are an integral body. One of the right-angle faces of the corner cube prism is in close contact with the depolarizing beam splitter prism, and the included angle with the semi-transparent and semi-reflective surface in the depolarizing beam splitter prism is 45°.

[0023] In the above solution, the incident surface of the sample to be measured is a smooth surface, and the back surface is not polished or coated with an anti-reflection film, which can improve the brightness of the reflected light after the light beam passes through the sample to be measured, making it easier for the power meter to receive the light beam and reducing the measurement error.

[0024] In the above solution, using the normal incidence module to make the included angle between the two light beams entering the autocollimator 9 less than 5″ can make the reflected light of the sample to be measured enter the semi-transparent and semi-reflective mirror at an incident angle of 45°, which is the same as the incident angle of the previous light source. By controlling other factors except the target variable to be unchanged, the interference of these factors on the result can be eliminated, making the evaluation more accurate and improving the accuracy and reliability of the test device.

[0025] In the above technical solution, the device needs to be carried out in a dark and dust-free environment, which can reduce the influence of other light sources on the test process and improve the accuracy of the test results.

[0026] In the above solution, the device can also measure the refractive index of optical products. It is required that the incident surface of the sample to be measured 3 is a smooth surface and not coated, and the back surface is not polished or coated with an anti-reflection film; the 0° reflectivity R of the sample is measured. According to the Fresnel formula R = (n - 1) 2 / (n + 1) 2 the refractive index of the sample can be calculated .

[0027] Compared with the prior art, the beneficial effects of the present utility model are:

[0028] The optical path of this device is relatively simple, easy to adjust, and can measure the 0° reflectivity of optical products relatively quickly;

[0029] This device has low requirements for the incident angle, but can accurately measure the 0° reflectivity, and has high practicality;

[0030] This device has a small test distance, reduces the energy propagation loss, and increases the accuracy of the test results;

[0031] This device can not only measure the 0° reflectivity of optical products, but also test the refractive index of optical products. It has strong practicability and can be used in different scenarios. Brief Description of the Drawings

[0032] Figure 1 It is a schematic optical path diagram for measuring the 0° reflectivity of an optical product of the present utility model;

[0033] Figure 2 It is a schematic structural diagram of a device for measuring the 0° reflectivity of an optical product of the present utility model;

[0034] Figure 3 It is a structural diagram of a light source fixing bracket;

[0035] Figure 4 It is a structural diagram of a five-dimensional adjustment bracket for a semi-transparent and semi-reflective mirror;

[0036] Figure 5 It is a structural diagram of a five-dimensional adjustment bracket for a sample to be measured;

[0037] In the figure: 1. Light source; 2. Semi-transparent and semi-reflective mirror; 3. Sample to be measured; 4. Power meter; 5. Power meter; 6. Normal incidence module; 7. Corner cube prism; 8. Depolarization beam splitter prism; 9. Autocollimator; 10. Light source fixing bracket; 11. Five-dimensional adjustment bracket; 12. Five-dimensional adjustment bracket. Detailed Embodiment

[0038] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the drawings in the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0039] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise stated, the meaning of "a plurality" is two or more.

[0040] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific situations.

[0041] Such as Figure 1 Build a device for measuring the 0° reflectivity of an optical product, including a light source 1, a power meter 4 and a power meter 5, as well as a first optical path and a second optical path arranged between the light source 1 and the two power meters. Among them, the light emitted by the light source 1 enters the first optical path and is output to the power meter 4 via the semi-transparent and semi-reflective mirror 2; after the light emitted by the light source 1 enters the second optical path, it is reflected back to the normal incidence module 6 and the semi-transparent and semi-reflective mirror 2 via the semi-transparent and semi-reflective mirror 2, the normal incidence module 6, and the sample to be measured 3, and then output to the power meter 5. Such as Figure 4 Structural diagram of a five-dimensional adjustment frame for a semi-transparent and semi-reflective mirror. Adjust the five-dimensional adjustment frame 11 that fixes the semi-transparent and semi-reflective mirror 2 so that the light emitted by the light source enters the semi-transparent and semi-reflective mirror 2 at an angle of 45° ± 2°.

[0042] Use such as Figure 3 Adjusting device for the light source fixing frame. Adjust the height of the light source fixing frame 10 to ensure that the light source can pass through the semi-transparent and semi-reflective mirror 2. Adjust the five-dimensional adjustment frame 11 so that the angle between the semi-transparent and semi-reflective mirror 2 and the light ray is 45°, with an error of 2°.

[0043] Place the power meter 4 and the power meter 5 at Figure 1 the positions shown to measure the refracted light power P1 and the transmitted light power P2.

[0044] Place the power meter 4 on the optical path where the light is refracted by the semi-transparent and semi-reflective mirror 2. Since the splitting ratio of the semi-transparent and semi-reflective mirror 2 is 50 / 50, the refracted light is perpendicular to the incident light and forms an angle of 45° with the semi-transparent and semi-reflective mirror. Therefore, the power meter 4 can receive the refracted light at the shown position and measure the power as P1.

[0045] Place the power meter 5 on the optical path where the light passes through the semi-transparent and semi-reflective mirror 2, and then the transmitted light P2 can be measured.

[0046] Place the sample 3 to be measured and the normal incidence module 6 at the positions as shown in Figure 2 shown, and adjust and fix the five-dimensional adjustment frame 12 of the sample 3 to be measured through the five-dimensional adjustment frame structure diagram of the sample 3 to be measured as shown in Figure 5 such that the angle between the two beams of light entering the autocollimator 9 is <5″. Remove the normal incidence module 6. At this time, the light is normally incident on the sample 3 to be measured.

[0047] The normal incidence module 6 is composed of a corner cube prism 7, a depolarizing beam splitter prism 8, and an autocollimator 9. Among them, the corner cube prism 7 and the depolarizing beam splitter prism 8 are an integral body. One of the right-angled surfaces of the corner cube prism 7 is in close contact with the depolarizing beam splitter prism 8 and forms an angle of 45° with the semi-transparent and semi-reflective surface in the depolarizing beam splitter prism 8. The autocollimator 9 is placed opposite to the depolarizing beam splitter prism 8. When the light reflected from the sample 3 to be measured passes through the corner cube prism 7 and the depolarizing beam splitter prism 8 and the light directly refracted by the semi-transparent and semi-reflective surface of the depolarizing beam splitter prism 8 enter the autocollimator 9 together, the two beams of light are parallel, and the error angle cannot exceed 5″.

[0048] This step is to ensure that the angle between the light reflected after entering the fixed sample 3 to be measured and the incident light is 0°.

[0049] The power meter 5 measures the refracted light power P3 after the light reflected from the sample 3 to be measured passes through the semi-transparent and semi-reflective surface at the position shown in Figure 2 shown.

[0050] Since the splitting ratio of the semi-transparent and semi-reflective mirror 2 is 50 / 50, the refracted light is perpendicular to the incident light and forms an angle of 45° with the semi-transparent and semi-reflective mirror. Therefore, the power meter 5 can receive the refracted light at the shown position and measure the power as P3.

[0051] Assume that the power transmitted through the semi-transparent and semi-reflective mirror after the reflected light of the sample 3 to be measured is P4. According to the principle of energy conservation, the equation can be obtained: P1 / P2 = P3 / P4;

[0052] According to the reflectivity R = reflected light power / incident light power, the incident light power is P2, and the reflected light power is P3 + P4. Then R = (P3 + P4) / P2;

[0053] So P4 = P2×P3 / P1;

[0054] The 0° reflectivity formula of the sample to be measured 3 is: R = P3(P1 + P2) / (P1 × P2).

[0055] This device can also measure the refractive index of optical products. It is required that the incident surface of the sample to be measured 3 is a smooth surface without coating, and the back surface is not polished or coated with an antireflection film; measure the reflectivity R of the sample at 0°, and according to the Fresnel formula R = (n - 1) 2 / (n + 1) 2 the refractive index of the sample can be calculated .

[0056] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for measuring the 0° reflectivity of an optical product, characterized in that: The invention comprises a light source, two power meters, and a first optical path and a second optical path arranged between the light source and the two power meters, wherein the light emitted by the light source enters the first optical path and is output to the first power meter via a semi-transparent and semi-reflective mirror; after the light emitted by the light source enters the second optical path, it is reflected back to the normal incidence module and the semi-transparent and semi-reflective mirror via the semi-transparent and semi-reflective mirror, the normal incidence module, and the sample to be measured, and is output to the second power meter.

2. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: The light source is fixed by a light source fixing frame, and the semi-transparent and semi-reflective mirrors and the sample to be tested are fixed by five-dimensional adjustment frames respectively.

3. The device for measuring 0° reflectivity of an optical product according to claim 2, characterized in that: The five-dimensional adjustment frame is used to adjust the height and angle of the semi-transparent and semi-reflective mirrors or the samples to be tested.

4. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: The light source emits collimated polarized light, and the polarization direction is parallel to the horizontal plane.

5. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: The splitting ratio of the semi-transparent and semi-reflective mirror is 50 / 50, and the surface of the semi-transparent and semi-reflective mirror facing the light source is coated with an anti-reflection film, and the surface away from the light source is coated with a dichroic film.

6. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: The incident surface of the sample to be tested is a smooth surface, and the back surface is not polished or coated with an anti-reflection film.

7. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: When the light beam emitted by the light source enters the semi-transparent and semi-reflective mirror, the angle between the light beam and the semi-transparent and semi-reflective mirror is 45°.

8. The device for measuring 0° reflectivity of an optical product according to claim 1, characterized in that: The normal-incidence module comprises a corner cube prism, a depolarizing beam splitter prism, and an autocollimator, wherein the depolarizing beam splitter prism has a beam splitting ratio of 50 / 50.

9. The device for measuring 0° reflectivity of an optical product according to claim 8, characterized in that: In the normal incidence module, the corner cube prism and the depolarizing beam splitter prism are integrated, one of the right-angled surfaces of the corner cube prism is in close contact with the depolarizing beam splitter prism, and the angle between the corner cube prism and the semi-transparent and semi-reflective surface of the depolarizing beam splitter prism is 45°.

Images