Optical device, grating diffraction efficiency testing device, system, method and controller

Abstract

The invention discloses an optical device, a grating diffraction efficiency testing device, a grating diffraction efficiency testing system, a grating diffraction efficiency testing method and a controller, probe light with different incident angles enters a grating through the optical device, diffraction light is generated after the probe light is diffracted by the grating, and the diffraction light is emitted out of the optical device so as to carry out diffraction efficiency testing on the grating, and the detection light and the corresponding diffraction light with different incident angles have the same optical path in the optical device. Therefore, due to the fact that the optical paths of the probe light of different incident angles in the optical device are the same, it is guaranteed that the probe light of different incident angles has the same optical loss when propagating in the optical device, and due to the fact that the optical paths of different diffracted light in the optical device are also the same, the optical loss of the probe light can be reduced. Therefore, it is ensured that different diffracted light has the same light loss when propagating in the optical device, the influence of the light loss in the optical device is reduced, and the accuracy of diffraction efficiency testing is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of grating testing, and in particular to an optical device, a grating diffraction efficiency testing device, a system, a method and a controller. Background Art

[0002] With the rapid development of optical technology, gratings are widely used in the optical field as important diffraction components. The diffraction efficiency of the grating determines the quality of the grating, so it is necessary to accurately test the diffraction efficiency of the grating.

[0003] In the related art, when testing the diffraction efficiency of a grating, it is necessary to measure the detection light power P1 of the light beam before it is incident on the prism, and the diffraction light power P2 of the light beam refracted from the prism into the air, and calculate the diffraction efficiency of the grating by the ratio of the two light powers P2 / P1. However, when the detection light of different incident angles is incident on the grating, the detection light of different incident angles has different light losses (i.e., light power losses) when propagating in the prism, and the diffracted light formed by the detection light of different incident angles has different exit angles, and the diffracted light of different exit angles also has different light losses when propagating in the prism, which greatly affects the accuracy of the grating diffraction efficiency test. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first purpose of the present invention is to provide an optical device, since the optical paths of the detection lights with different incident angles in the optical device are the same, it is ensured that the detection lights with different incident angles have the same light loss when propagating in the optical device, and since the optical paths of the different diffracted lights in the optical device are also the same, it is ensured that the different diffracted lights have the same light loss when propagating in the optical device, which reduces the influence of the light loss in the optical device and is conducive to improving the accuracy of the diffraction efficiency test.

[0005] The second object of the present invention is to provide a grating diffraction efficiency testing device.

[0006] The third object of the present invention is to provide a grating diffraction efficiency testing system.

[0007] The fourth object of the present invention is to provide a method for testing grating diffraction efficiency.

[0008] A fifth object of the present invention is to provide a controller.

[0009] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes an optical device, wherein detection light of different incident angles is incident on a grating through the optical device, and diffracted by the grating to generate diffracted light that is emitted from the optical device, so as to test the diffraction efficiency of the grating, wherein the detection light of different incident angles and the corresponding diffracted light have the same optical path in the optical device.

[0010] According to the optical device of the embodiment of the present invention, when the diffraction efficiency of the grating is tested, the detection light with different incident angles is incident on the grating through the optical device, and the detection light is diffracted by the grating to generate diffracted light which is emitted from the optical device. Since the optical path of the detection light with different incident angles in the optical device is the same, it is ensured that the detection light with different incident angles has the same light loss when propagating in the optical device, and since the optical path of different diffracted lights in the optical device is also the same, it is ensured that different diffracted lights have the same light loss when propagating in the optical device, which reduces the influence of light loss in the optical device and helps to improve the accuracy of the diffraction efficiency test.

[0011] According to one embodiment of the present invention, the optical device includes a first prism having a first curved portion. Detection light of different incident angles is incident on a grating through the first curved portion, and diffracted by the grating to generate diffracted light that is emitted from the first curved portion, wherein the curvature at each point on the surface of the first curved portion is the same and the center of curvature coincides, and the center of curvature is located on the grating.

[0012] According to an embodiment of the present invention, the first curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism.

[0013] According to an embodiment of the present invention, the optical device further comprises a grating substrate, the grating substrate is located between the first prism and the grating, and the refractive index of the first prism is the same as the refractive index of the grating substrate.

[0014] According to an embodiment of the present invention, the center of curvature is located on a side surface of the grating close to the grating substrate; or, the center of curvature is located on a side surface of the grating away from the grating substrate; or, the center of curvature is located inside the grating.

[0015] According to an embodiment of the present invention, the grating is a reflective grating.

[0016] According to one embodiment of the present invention, the optical device includes a first prism and a second prism, the first prism has a first curved portion, the second prism has a second curved portion, detection light of different incident angles is incident on the grating through the first curved portion, and after diffraction by the grating, diffracted light is generated and emitted from the second curved portion, wherein the curvature at each surface point of the first curved portion is the same, the curvature at each surface point of the second curved portion is the same, the center of curvature at each surface point of the first curved portion coincides with the center of curvature at each surface point of the second curved portion, and the center of curvature is located on the grating.

[0017] According to an embodiment of the present invention, the first curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism, and the second curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism.

[0018] According to an embodiment of the present invention, the optical device further comprises a grating substrate, the grating substrate is located between the grating and the second prism, and the refractive index of the second prism is the same as the refractive index of the grating substrate.

[0019] According to an embodiment of the present invention, the center of curvature is located on a side surface of the grating close to the grating substrate; or, the center of curvature is located on a side surface of the grating away from the grating substrate; or, the center of curvature is located inside the grating.

[0020] According to an embodiment of the present invention, the grating is a transmission type grating.

[0021] According to one embodiment of the invention, the refractive index of the grating is different from the refractive index of the grating substrate.

[0022] According to an embodiment of the present invention, the grating is a one-dimensional grating or a two-dimensional grating.

[0023] To achieve the above-mentioned purpose, a second embodiment of the present invention provides a grating diffraction efficiency testing device, including the optical device as described in the first embodiment.

[0024] According to the grating diffraction efficiency testing device of the embodiment of the present invention, by providing the above-mentioned optical device, when the diffraction efficiency of the grating is tested, the detection light with different incident angles is incident on the grating through the optical device, and the detection light is diffracted by the grating to generate diffracted light that is emitted from the optical device. Since the detection light with different incident angles has the same optical path in the optical device, it is ensured that the detection light with different incident angles has the same optical loss when propagating in the optical device, and since the optical path of different diffracted lights in the optical device is also the same, it is ensured that different diffracted lights have the same optical loss when propagating in the optical device, which reduces the influence of light loss in the optical device and helps to improve the accuracy of the diffraction efficiency test.

[0025] According to one embodiment of the present invention, the device further includes:

[0026] Optical power meter, which is used to detect the power of diffracted light emitted from an optical device, so as to determine the diffraction efficiency of the grating based on the power of the diffracted light and the power of the detection light.

[0027] To achieve the above-mentioned purpose, a third aspect of the present invention provides a grating diffraction efficiency testing system, including a grating diffraction efficiency testing device as described in the second aspect of the present invention.

[0028] According to the grating diffraction efficiency testing system of the embodiment of the present invention, by being provided with the above-mentioned grating diffraction efficiency testing device, when the diffraction efficiency of the grating is tested, the detection light with different incident angles is incident on the grating through the optical device, and the detection light is diffracted by the grating to generate diffracted light which is emitted from the optical device. Since the detection light with different incident angles has the same optical path in the optical device, it is ensured that the detection light with different incident angles has the same optical loss when propagating in the optical device, and since the optical path of different diffracted lights in the optical device is also the same, it is ensured that different diffracted lights have the same optical loss when propagating in the optical device, thereby reducing the influence of light loss in the optical device, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0029] According to one embodiment of the present invention, the system also includes: a first rotating device and a second rotating device, the grating is driven to rotate by the first rotating device, and the optical power meter is driven to rotate by the second rotating device. When the grating is driven to rotate by the first rotating device, the optical power meter follows the grating rotation via the second rotating device.

[0030] To achieve the above-mentioned purpose, a fourth aspect of the present invention provides a grating diffraction efficiency test method, which is applied to the grating diffraction efficiency test system in the third aspect of the present invention. The method includes:

[0031] detecting the power of diffracted light emitted from the optical device;

[0032] The diffraction efficiency of the grating is determined based on the power of the diffracted light and the power of the probe light.

[0033] According to the grating diffraction efficiency testing method of the embodiment of the present invention, the power of the diffracted light emitted from the optical device is detected, and the diffraction efficiency of the grating is determined according to the power of the diffracted light and the power of the detection light. Since the detection light with different incident angles has the same optical path in the optical device, it is ensured that the detection light with different incident angles has the same optical loss when propagating in the optical device. Since the optical path of different diffracted lights in the optical device is also the same, it is ensured that different diffracted lights have the same optical loss when propagating in the optical device, which reduces the influence of the optical loss in the optical device and is conducive to improving the accuracy of the diffraction efficiency test.

[0034] According to one embodiment of the present invention, when the grating is a reflective grating, determining the diffraction efficiency of the grating according to the power of the diffracted light and the power of the detection light includes:

[0035] Obtaining a ratio of the power of the diffracted light to the optical power loss rate of the first prism to obtain a first ratio;

[0036] Obtaining the product of the power of the detection light and the optical power loss rate of the first prism to obtain a second ratio;

[0037] The diffraction efficiency of the grating is determined based on the first ratio and the second ratio.

[0038] According to one embodiment of the present invention, when the grating is a transmission type grating, the diffraction efficiency of the grating is determined according to the power of the diffracted light and the power of the detection light, including:

[0039] Obtaining a ratio of the power of the diffracted light to the optical power loss rate of the second prism to obtain a third ratio;

[0040] Obtaining the product of the power of the detection light and the optical power loss rate of the first prism to obtain a fourth ratio;

[0041] The diffraction efficiency of the grating is determined according to the third ratio and the fourth ratio.

[0042] According to one embodiment of the present invention, the method further includes:

[0043] The rotation angle of the second rotating device is determined according to the rotation angle of the first rotating device.

[0044] According to one embodiment of the present invention, determining the rotation angle of the second rotation device according to the rotation angle of the first rotation device includes:

[0045] Determine a reference grating vector of the grating based on a first reference light vector of the reference detection light in the grating and a second reference light vector of the reference diffracted light corresponding to the reference detection light in the grating;

[0046] When the first rotating device rotates by a preset angle, the rotating angle of the second rotating device is determined according to the preset angle, the first reference light vector, the second reference light vector and the reference grating vector.

[0047] According to one embodiment of the present invention, determining the rotation angle of the second rotating device according to the preset angle, the first reference light vector, the second reference light vector and the reference grating vector includes:

[0048] Determine a first light vector of the rotated detection light according to a preset angle and a first reference light vector;

[0049] Determine a second light vector of the rotated diffracted light according to the first light vector and the reference grating vector;

[0050] The rotation angle of the second rotating device is determined according to the second light vector and the second reference light vector.

[0051] According to one embodiment of the present invention, the method further includes:

[0052] Obtain the grating vector of the grating when the diffraction efficiency is maximum;

[0053] Check whether the raster is qualified based on the raster vector.

[0054] To achieve the above-mentioned purpose, the fifth aspect of the present invention proposes a controller, which is characterized in that it includes: a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the grating diffraction efficiency test method in the fourth aspect of the embodiment is implemented.

[0055] According to the controller of the embodiment of the present invention, through the above-mentioned grating diffraction efficiency testing method, since the optical path of the detection light with different incident angles in the optical device is the same, it is ensured that the detection light with different incident angles has the same light loss when propagating in the optical device, and since the optical path of different diffracted lights in the optical device is also the same, it is ensured that different diffracted lights have the same light loss when propagating in the optical device, which reduces the influence of light loss in the optical device and is beneficial to improving the accuracy of the diffraction efficiency test.

[0056] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic diagram of a grating diffraction efficiency testing system according to an embodiment of the present invention;

[0058] Figure 2 is a schematic diagram of a first prism having a curvature center located inside a grating according to an embodiment of the present invention;

[0059] Figure 3 is a schematic diagram of a first prism in which the center of curvature is located on a surface of the grating away from the first prism according to an embodiment of the present invention;

[0060] Figure 4 is a schematic diagram of a first prism in which the center of curvature is located on a surface of a grating close to the first prism according to an embodiment of the present invention;

[0061] Figure 5 is a schematic diagram of a first prism, a grating substrate and a grating according to an embodiment of the present invention;

[0062] Figure 6 is a schematic diagram of a first prism, a second prism and a grating according to an embodiment of the present invention;

[0063] Figure 7 is a schematic diagram of a first prism, a second prism, a grating substrate and a grating according to an embodiment of the present invention;

[0064] Figure 8 is a schematic diagram of a first prism and a grating according to an embodiment of the present invention;

[0065] Fig. 9is a schematic diagram of a first prism according to an embodiment of the present invention;

[0066] Fig.10 is a schematic diagram of a first prism and a grating substrate according to an embodiment of the present invention;

[0067] Fig.11 is a schematic diagram of a second prism according to an embodiment of the present invention;

[0068] Fig.12 is a schematic diagram of a second prism and a grating substrate according to an embodiment of the present invention;

[0069] Fig.13 A stereogram and a projection diagram of a grating diffraction efficiency testing device corresponding to a one-dimensional grating according to an embodiment of the present invention;

[0070] Fig.14 A three-dimensional diagram of a grating diffraction efficiency testing device corresponding to a two-dimensional grating according to an embodiment of the present invention;

[0071] Fig.15 A schematic diagram of a flow chart of a method for testing grating diffraction efficiency according to an embodiment of the present invention;

[0072] Fig.16 is a diagram showing the relationship between the rotation angle of the first rotating device and the rotation angle of the second rotating device according to an embodiment of the present invention;

[0073] Fig.17 (a) is a schematic diagram of the angle of the detection light and the angle of the diffracted light when designed according to one embodiment of the present invention;

[0074] Fig.17 (b) is a schematic diagram of the incident angle of the detection light and the exit angle of the diffracted light when the diffraction efficiency is maximum according to one embodiment of the present invention;

[0075] Fig.18 is a schematic block diagram of a controller according to an embodiment of the present invention.

[0076] Reference numerals:

[0077] Grating diffraction efficiency testing system 100;

[0078] Grating diffraction efficiency testing device 10;

[0079] Optical device 1; detection light 11;

[0080] First prism 2; first curved portion 21;

[0081] Optical power meter 3;

[0082] Grating 4; diffracted light 41;

[0083] Second prism 5; second curved portion 51;

[0084] Grating substrate 6;

[0085] A first rotating device 7;

[0086] A second rotating device 8;

[0087] Center of curvature P;

[0088] Controller 200;

[0089] Memory 210 ; processor 220 . DETAILED DESCRIPTION

[0090] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0091] The following describes an optical device 1, a grating diffraction efficiency testing device 10, a grating diffraction efficiency testing system 100, a grating diffraction efficiency testing method and a controller 200 proposed in an embodiment of the present invention with reference to the accompanying drawings.

[0092] like Figure 1-Figure 14 As shown, according to the optical device 1 of the first aspect of the embodiment of the present invention, the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, and is diffracted by the grating 4 to generate diffraction light 41 which is emitted from the optical device 1 to test the diffraction efficiency of the grating 4, wherein the detection light 11 with different incident angles and the corresponding diffraction light 41 have the same optical path in the optical device 1.

[0093] Specifically, the light source is used to emit detection light 11 with different incident angles to the optical device 1. It can be understood that before the detection light 11 is incident on the grating 4, the power of the detection light 11 needs to be detected. Optionally, a detection device can be set inside the light source, or a detection device can be set at the outlet of the light source to detect the power of the detection light 11 before the detection light 11 is incident on the optical device 1. The specific setting method is selected according to actual needs and is not specifically limited here.

[0094] When the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, the detection light 11 is diffracted by the grating 4 to generate diffraction light 41 which is emitted from the optical device 1. With such a setting, the diffraction efficiency of the grating 4 can be tested by obtaining the power of the diffraction light 41 emitted from the optical device 1 and the power of the detection light 11 obtained in the early stage.

[0095] It should be noted that when the detection light 11 is incident on the grating 4 at different angles, the corresponding diffraction light 41 generated by the detection light 11 after diffraction by the grating 4 also has different exit angles. At the same time, when the detection light 11 and the diffraction light 41 are transmitted in the optical device 1, the detection light 11 and the diffraction light 41 will experience power attenuation. If the detection light 11 and the corresponding diffraction light 41 with different incident angles have different optical path lengths in the optical device 1, the detection light 11 and the corresponding diffraction light 41 with different incident angles will experience different degrees of power attenuation when propagating in the optical device 1, which greatly reduces the accuracy of the diffraction efficiency test.

[0096] Based on this, the present application ensures that the optical paths of the detection light 11 with different incident angles and the corresponding diffracted light 41 in the optical device 1 are the same, so that the power loss of the detection light 11 with different incident angles when entering the grating 4 through the optical device 1 is the same, and the power loss of the corresponding diffracted light 41 when emitted through the optical device 1 is also the same, thereby ensuring the consistency of the power loss of the detection light 11 in the optical device 1 and the consistency of the power loss of the diffracted light 41 in the optical device 1, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0097] According to the optical device 1 of the embodiment of the present invention, when the diffraction efficiency of the grating 4 is tested, the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1. The detection light 11 is diffracted by the grating 4 and generates diffraction light 41 which is emitted from the optical device 1. Since the optical path of the detection light 11 with different incident angles in the optical device 1 is the same, it is ensured that the detection light 11 with different incident angles has the same light loss when propagating in the optical device 1. Since the optical path of different diffraction lights 41 in the optical device 1 is also the same, it is ensured that different diffraction lights 41 have the same light loss when propagating in the optical device 1, which reduces the influence of light loss in the optical device 1 and helps to improve the accuracy of the diffraction efficiency test.

[0098] In some embodiments of the present invention, Figure 2 As shown, the optical device 1 includes a first prism 2, and the first prism 2 has a first curved portion 21. The detection light 11 with different incident angles is incident on the grating 4 through the first curved portion 21, and is diffracted by the grating 4 to generate diffracted light 41 that is emitted from the first curved portion 21, wherein the curvature at each point on the surface of the first curved portion 21 is the same and the center of curvature P coincides, and the center of curvature P is located on the grating 4.

[0099] Specifically, the curvature at each point on the surface of the first curved portion 21 of the first prism 2 is the same and the center of curvature P coincides. That is to say, when the detection light 11 of different incident angles is incident on the first prism 2 through the first curved portion 21, it is ensured that the detection light 11 of different incident angles is incident on the first prism 2. The center of curvature P, and because the curvature at each point on the first curved portion 21 is the same, it is ensured that the optical path of the detection light 11 of different incident angles from the incident point of the first prism 2 to the center of curvature P is the same.

[0100] Furthermore, the detection light 11 generates diffracted light 41 after being diffracted by the grating 4 and is reflected from the grating 4 to the first prism 2. Since the center of curvature P of the first prism 2 is located on the grating 4, as shown in FIG. Figure 2-Figure 4 As shown, the diffracted light 41 generated by the grating 4 is emitted from the center of curvature P to the first prism 2, and since the curvature at each point of the first curved surface portion 21 is the same, it is ensured that the diffracted light 41 with different exit angles has the same optical path in the first prism 2.

[0101] Therefore, by setting the first curved portion 21 with the same curvature and the same curvature center P at each point on the surface of the first prism 2, the optical path of the detection light 11 with different incident angles in the first prism 2 is the same, and the optical path of the diffracted light 41 with different emergent angles in the first prism 2 is the same, thereby ensuring the consistency of the optical loss of different detection lights 11 in the first prism 2 and the consistency of the optical loss of different diffracted lights 41 in the first prism 2, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0102] In some embodiments of the present invention, Figure 2-Figure 5 As shown, the first curved surface portion 21 is the curved surface of a cylindrical prism or the curved surface of a spherical prism. That is to say, the first curved surface portion 21 can be constructed as the curved surface of a cylindrical prism, and can also be constructed as the curved surface of a spherical prism. For example, the first curved surface portion 21 may not be a whole surface, such as the first prism 2 can be half or a quarter of a cylindrical prism, and the first prism 2 can also be half or a quarter of a spherical prism. Such an arrangement ensures that the first curved surface portion 21 has the same curvature and the curvature center P coincides, and both the cylindrical prism and the spherical prism are easy to manufacture, which simplifies the manufacturing difficulty of the first prism 2.

[0103] In some embodiments of the present invention, Figure 2-Figure 5 As shown, the optical device 1 further includes a grating substrate 6 , which is located between the first prism 2 and the grating 4 , and the refractive index of the first prism 2 is the same as the refractive index of the grating substrate 6 .

[0104] Specifically, the optical device 1 may further include a grating substrate 6. Optionally, the grating substrate 6 is a glass matching liquid having the same refractive index as the first prism 2. The first prism 2 is bonded to the grating 4 through the glass matching liquid. The glass matching liquid eventually solidifies into the grating substrate 6 and is located between the first prism 2 and the grating 4. The grating substrate 6 has the same refractive index as the first prism 2. Figure 2-Figure 5 As shown, when the detection light 11 is incident from the first prism 2 into the grating substrate 6, the detection light 11 will not be refracted at the junction of the first prism 2 and the grating substrate 6 to cause the direction of the light to change, thereby ensuring the consistency of the transmission direction of the detection light 11, that is, the direction of the detection light 11 will not change during the transmission process between the first prism 2 and the grating substrate 6. Further, continue to refer to Figure 2-Figure 5 As shown, the diffracted light 41 is incident on the first prism 2 through the grating substrate 6. Since the refractive index of the first prism 2 is the same as that of the grating substrate 6, the diffracted light 41 will not be refracted at the junction of the first prism 2 and the grating substrate 6, which will cause the direction of the light to change, thereby ensuring the consistency of the transmission direction of the diffracted light 41, that is, the direction of the diffracted light 41 will not change during the transmission between the first prism 2 and the grating substrate 6, thereby ensuring that the detection light 11 and the diffracted light 41 have the same optical path during the transmission between the first prism 2 and the grating substrate 6.

[0105] It should be noted that the grating substrate 6 may not be disposed between the first prism 2 and the grating 4. That is, if the grating substrate 6 between the first prism 2 and the grating 4 is to be removed during the test to eliminate the influence of the grating substrate 6 on the loss of optical power, a "conjugate" method may be used, such as Figure 8 As shown, the bonding operation of the refractive index glass matching liquid can be omitted, and the first prism 2 is a hemispherical curved prism.

[0106] In some embodiments of the present invention, Figure 2-Figure 4 As shown, the curvature center P is located on the side surface of the grating 4 close to the grating substrate 6; or, the curvature center P is located on the side surface of the grating 4 away from the grating substrate 6; or, the curvature center P is located inside the grating 4. In other words, Figure 2 As shown, the center of curvature P can be located inside the grating 4, such as Figure 3 As shown, the center of curvature P may also be located on the side surface of the grating 4 away from the grating substrate 6, such as Figure 4 As shown, the center of curvature P can also be located on one side surface of the grating 4 close to the grating substrate 6, that is, it is sufficient to ensure that the center of curvature P of the first prism 2 is located on the grating 4. There is no specific limitation here. Since the thickness of the grating 4 is relatively thin, the light loss on the grating 4 can be ignored when actually calculating the light loss. With this arrangement, it can be approximately considered that the light loss of the detection light 11 with different incident angles in the first prism 2 is the same, and the light loss of the corresponding diffracted light 41 in the first prism 2 is the same.

[0107] In some embodiments of the present invention, the grating 4 is a reflective grating. Figure 2-Figure 5 As shown, the reflective grating is used to reflect the detection light 11. The first prism 2 of the optical device 1 is located on one side of the grating 4. When the light source emits the detection light 11 with different incident angles to the grating 4, the detection light 11 with different incident angles is incident on the grating 4 through the first prism 2. After the detection light 11 is incident on the grating 4, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 and is reflected from the grating 4 to the first prism 2. The diffracted light 41 passes through the first prism 2 and then is emitted from the first prism 2. It can be understood that the detection light 11 with different incident angles and the corresponding diffracted light 41 have the same optical path in the first prism 2, that is, That is to say, the power loss of the detection light 11 with different incident angles when it is incident on the grating 4 through the first prism 2 is the same, and the power loss of the corresponding diffraction light 41 when it is emitted through the first prism 2 is also the same, thereby ensuring the consistency of the light loss of different detection lights 11 in the first prism 2, and the consistency of the light loss of different diffraction lights 41 in the first prism 2, which is beneficial to improving the accuracy of the diffraction efficiency test. At the same time, the first prism 2 is used to transmit the detection light 11 and the diffraction light 41, and ensure that the detection light 11 and the diffraction light 41 are located on the same side of the grating 4, which is convenient for the diffraction efficiency test of the grating 4.

[0108] In some embodiments of the present invention, Figure 6 and Figure 7 As shown, the optical device 1 includes a first prism 2 and a second prism 5, the first prism 2 has a first curved portion 21, the second prism 5 has a second curved portion 51, the detection light 11 of different incident angles is incident on the grating 4 through the first curved portion 21, and is diffracted by the grating 4 to generate diffracted light 41 emitted from the second curved portion 51, wherein the curvature at each surface point of the first curved portion 21 is the same, the curvature at each surface point of the second curved portion 51 is the same, the curvature center P at each surface point of the first curved portion 21 coincides with the curvature center P at each surface point of the second curved portion 51, and the curvature center P is located on the grating 4.

[0109] Specifically, when the detection light 11 of different incident angles is incident on the first prism 2 through the first curved portion 21, it is ensured that the detection light 11 of different incident angles is incident on the first prism 2 at the center of curvature P where the first curved portion 21 and the second curved portion 51 coincide. Since the curvature at each point on the surface of the first curved portion 21 is the same, it is ensured that the optical path of the detection light 11 of different incident angles from the incident point of the first prism 2 to the center of curvature P is the same. Further, the detection light 11 of different incident angles is incident on the grating 4 after passing through the first prism 2. The detection light 11 is diffracted by the grating 4 to generate diffracted light 41. Since the grating 4 is located at the center of curvature P where the first curved portion 21 and the second curved portion 51 coincide, as shown in FIG. Figure 6As shown, the diffracted light 41 generated by the grating 4 is emitted from the center of curvature P to the second prism 5 , and since the curvature at each point of the second curved surface 51 is the same, it is ensured that the diffracted light 41 with different exit angles has the same optical path in the second prism 5 .

[0110] Therefore, the first prism 2 and the second prism 5 are respectively arranged to ensure that the curvature at each point on the surface of the first curved portion 21 of the first prism 2 is the same, and the curvature at each point on the surface of the second curved portion 51 of the second prism 5 is the same, and at the same time, the curvature center P at each point on the surface of the first curved portion 21 coincides with the curvature center P at each point on the surface of the second curved portion 51, so that the optical path of the detection light 11 with different incident angles in the first prism 2 is the same, and the optical path of the diffracted light 41 with different emergent angles in the second prism 5 is the same, thereby ensuring the consistency of the optical loss of different detection lights 11 in the first prism 2 and the consistency of the optical loss of different diffracted lights 41 in the second prism 5, which is beneficial to improving the accuracy of testing the diffraction efficiency of the grating 4 using the first prism 2 and the second prism 5.

[0111] It should be noted that the curvature of the first curved surface portion 21 and the curvature of the second curved surface portion 51 can be the same or different, as long as the curvature center P at each surface point of the first curved surface portion 21 coincides with the curvature center P at each surface point of the second curved surface portion 51. No specific restrictions are made here.

[0112] In some embodiments of the present invention, Figure 6 and Figure 7 As shown, the first curved portion 21 is the curved surface of a cylindrical prism or the curved surface of a spherical prism, and the second curved portion 51 is the curved surface of a cylindrical prism or the curved surface of a spherical prism. That is to say, the first curved portion 21 can be configured as the curved surface of a cylindrical prism or the curved surface of a spherical prism, and the second curved portion 51 can be configured as the curved surface of a cylindrical prism or the curved surface of a spherical prism. For example, the first prism 2 can be half or a quarter of a cylindrical prism, and the first prism 2 can also be half or a quarter of a spherical prism. The second prism 5 can be half or a quarter of a cylindrical prism, and the second prism 5 can also be half or a quarter of a spherical prism. Further, as a specific example, the first prism 2 and the second prism 5 can be set as two halves of a spherical prism with the same curvature, or can be set as two halves of a spherical prism with different curvatures, and it is ensured that after being installed in conjunction with the grating 4, the center of curvature P of the first prism 2 coincides with the center of curvature P of the second prism 5. This arrangement ensures that the optical path of the detection light 11 with different incident angles in the first prism 2 is the same, and the optical path of the diffracted light 41 with different exit angles in the second prism 5 is the same, and the first prism 2 and the second prism 5 of the cylindrical prism or the spherical prism are easy to manufacture and produce, which simplifies the manufacturing difficulty of the first prism 2 and the second prism 5.

[0113] In some embodiments of the present invention, Figure 7 As shown, the optical device 1 further includes a grating substrate 6 , which is located between the grating 4 and the second prism 5 , and the refractive index of the second prism 5 is the same as the refractive index of the grating substrate 6 .

[0114] Specifically, a grating substrate 6 may be provided between the grating 4 and the second prism 5. The grating substrate 6 is a glass matching liquid having the same refractive index as the second prism 5. The second prism 5 is bonded to the grating 4 through the glass matching liquid. The glass matching liquid eventually solidifies into the grating substrate 6 and is located between the second prism 5 and the grating 4. The grating substrate 6 has the same refractive index as the second prism 5. Figure 7 As shown, when the diffracted light 41 is emitted from the grating 4, the diffracted light 41 passes through the grating substrate 6 and the second prism 5 in sequence. The refractive index of the second prism 5 is the same as that of the grating substrate 6. The diffracted light 41 will not be refracted at the junction of the second prism 5 and the grating substrate 6, resulting in a change in the direction of the light, thereby ensuring the consistency of the transmission direction of the diffracted light 41, that is, the direction of the diffracted light 41 will not change during the transmission process between the second prism 5 and the grating substrate 6, ensuring that the diffracted light 41 with different exit angles has the same optical path in the second prism 5 and the grating substrate 6.

[0115] It should be noted that if Figure 6 As shown, the grating substrate 6 may not be arranged between the second prism 5 and the grating 4, that is, the grating substrate 6 between the second prism 5 and the grating 4 is removed during testing, thereby eliminating the influence of the grating substrate 6 on the loss of optical power and saving a bonding operation of the refractive index glass matching liquid.

[0116] In some embodiments of the present invention, Figure 2-Figure 4 As shown, the curvature center P is located on the side surface of the grating 4 close to the grating substrate 6; or, the curvature center P is located on the side surface of the grating 4 away from the grating substrate 6; or, the curvature center P is located inside the grating 4. In other words, Figure 2 As shown, the center of curvature P can be located inside the grating 4, such as Figure 3 As shown, the center of curvature P may also be located on the side surface of the grating 4 away from the grating substrate 6, such as Figure 4 As shown, the center of curvature P can also be located on one side surface of the grating 4 close to the grating substrate 6, that is, it is sufficient to ensure that the center of curvature P of the first prism 2 is located on the grating 4. There is no specific limitation here. Since the thickness of the grating 4 is relatively thin, the light loss on the grating 4 can be ignored when actually calculating the light loss. This arrangement can ensure that the light loss of the detection light 11 with different incident angles in the first prism 2 is the same, and the light loss of the corresponding diffracted light 41 in the first prism 2 is the same.

[0117] In some embodiments of the present invention, Figure 6and Figure 7 As shown, the grating 4 is a transmission type grating. Specifically, as Figure 6 and Figure 7 As shown, the transmission grating is used to transmit the detection light 11, the first prism 2 and the second prism 5 are respectively located on both sides of the grating 4. When the light source emits the detection light 11 with different incident angles to the grating 4, the detection light 11 with different incident angles is incident on the grating 4 through the first prism 2. After the detection light 11 is incident on the grating 4, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 and is transmitted from the grating 4 to the second prism 5. The diffracted light 41 passes through the second prism 5 and then is emitted from the second prism 5. It can be understood that the detection light 11 with different incident angles The optical path of the detection light 11 in the first prism 2 is the same, and the optical path of the corresponding diffracted light 41 in the second prism 5 is the same, that is, the power loss of the detection light 11 with different incident angles when it is incident on the grating 4 through the first prism 2 is the same, and the power loss of the corresponding diffracted light 41 when it is emitted through the second prism 5 is also the same, thereby ensuring the consistency of the optical loss of the detection light 11 with different incident angles in the first prism 2 and the consistency of the optical loss of the corresponding diffracted light 41 in the second prism 5, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0118] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the refractive index of the grating 4 is different from the refractive index of the grating substrate 6. Specifically, the refractive index of the grating substrate 6 is exactly the same as the refractive index of the first prism 2, so the detection light 11 with different incident angles and the corresponding diffracted light 41 will not be refracted at the junction of the first prism 2 and the grating substrate 6, that is, the directions of the detection light 11 and the diffracted light 41 will not change during the transmission process between the first prism 2 and the grating substrate 6.

[0119] Furthermore, the refractive index of the grating 4 may be the same as or different from the refractive index of the grating substrate 6. When the refractive index of the grating 4 is different from the refractive index of the grating substrate 6, the detection light 11 of different incident angles and the corresponding diffracted light 41 will be refracted at the junction of the grating 4 and the grating substrate 6, thereby causing the detection light 11 and the diffracted light 41 to change direction during the transmission process between the grating 4 and the grating substrate 6. However, since the thickness of the grating 4 is relatively thin, it can be ignored, and it can be approximately considered that the detection light 41 and the diffracted light 41 both pass through the center of curvature P, and the curvature of each point on the surface of the first curved portion 21 of the first prism 2 is the same. With this arrangement, the detection light 11 of different incident angles has the same optical path when entering the grating 4 from the first prism 2, and the diffracted light 41 of different incident angles also has the same optical path when emitted from the first prism 2, thereby not affecting the diffraction efficiency test. When the refractive index of the grating 4 is the same as that of the grating substrate 6, the detection light 11 with different incident angles passes through the first prism 2, the grating substrate 6 and the grating 4 in a straight line to enter the curvature center P without being refracted, and the corresponding diffracted light 41 will also pass through the grating 4, the grating substrate 6 and the first prism 2 in a straight line to be emitted from the curvature center P without being refracted, and the detection light 11 with different incident angles has the same optical path when entering the grating 4 from the first prism 2 and the grating substrate 6, and the different diffracted light 41 also has the same optical path when being emitted from the grating substrate 6 and the first prism 2, so that it will not affect the diffraction efficiency test.

[0120] In some embodiments of the present invention, the grating 4 is a one-dimensional grating or a two-dimensional grating. Specifically, the grating 4 can be a one-dimensional grating or a two-dimensional grating. When the grating 4 is a one-dimensional grating, such as Fig.13 As shown, the propagation trajectory of the light beam is projected onto the plane where the detection light 11 and the diffracted light 41 are located, namely, the yz plane. The curvature of the first prism 2 is the same in the yz plane. The surface shape can be approximately regarded as a semi-cylindrical surface. The curvature center P of the surface is on the grating 4. When the detection light 11 is incident on the curvature center P, the optical path of the detection light 11 with different incident angles in the first prism 2 is the same, thereby ensuring the consistency of the light loss of the detection light 11 in the first prism 2 and reducing the influence of light loss when measuring the diffraction efficiency. When the grating 4 is a two-dimensional grating, as shown in FIG. Fig.14 As shown, the detection light 11 is in the zy plane, the diffraction light 41 is in the zx plane, and the curvature of the first prism 2 needs to be kept consistent at each point on the first curved surface portion 21 when testing the two-dimensional grating, and the curvature center P is on the grating 4.

[0121] like Fig.13 and Fig.14 As shown, a grating diffraction efficiency testing device 10 according to an embodiment of the second aspect of the present invention comprises an optical device 1 as in the embodiment of the first aspect.

[0122] According to the grating diffraction efficiency testing device 10 of the embodiment of the present invention, by being provided with the above-mentioned optical device 1, when the diffraction efficiency of the grating 4 is tested, the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, and the detection light 11 is diffracted by the grating 4 to generate diffraction light 41 which is emitted from the optical device 1. Since the optical path of the detection light 11 with different incident angles in the optical device 1 is the same, it is ensured that the detection light 11 with different incident angles has the same light loss when propagating in the optical device 1, and since the optical path of different diffraction lights 41 in the optical device 1 is also the same, it is ensured that different diffraction lights 41 have the same light loss when propagating in the optical device 1, thereby reducing the influence of light loss in the optical device 1, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0123] In some embodiments of the present invention, Fig.13 and Fig.14 As shown, the device also includes: an optical power meter 3, which is used to detect the power of the diffracted light 41 emitted from the optical device 1, so as to determine the diffraction efficiency of the grating 4 according to the power of the diffracted light 41 and the power of the detection light 11.

[0124] Specifically, before the detection light 11 is incident on the grating 4, the power of the detection light 11 needs to be detected. Optionally, a detection device can be set inside the light source, or at the exit of the light source, to detect the power of the detection light 11 before the detection light 11 is incident on the optical device 1. The detection device can be an optical power meter 3, or other power detection devices. When the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 with different exit angles and is emitted from the optical device 1. By adjusting the position of the optical power meter 3 so that the optical power meter 3 detects the power of the diffracted light 41 emitted from the optical device 1, the diffraction efficiency of the grating 4 is determined according to the detected power of the diffracted light 41 and the power of the detection light 11.

[0125] like Figure 1 As shown, a grating diffraction efficiency testing system 100 according to an embodiment of the third aspect of the present invention comprises a grating diffraction efficiency testing device 10 as in the embodiment of the second aspect.

[0126] According to the grating diffraction efficiency testing system 100 of the embodiment of the present invention, by being provided with the above-mentioned grating diffraction efficiency testing device 10, when the diffraction efficiency of the grating 4 is tested, the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, and the detection light 11 is diffracted by the grating 4 to generate diffraction light 41 which is emitted from the optical device 1. Since the optical path of the detection light 11 with different incident angles in the optical device 1 is the same, it is ensured that the detection light 11 with different incident angles has the same light loss when propagating in the optical device 1, and since the optical path of different diffraction lights 41 in the optical device 1 is also the same, it is ensured that different diffraction lights 41 have the same light loss when propagating in the optical device 1, thereby reducing the influence of light loss in the optical device 1, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0127] In some embodiments of the present invention, Figure 1 As shown, the system also includes: a first rotating device 7 and a second rotating device 8, the grating 4 is driven to rotate by the first rotating device 7, and the optical power meter 3 is driven to rotate by the second rotating device 8. When the grating 4 is driven to rotate by the first rotating device 7, the optical power meter 3 follows the grating 4 via the second rotating device 8.

[0128] It should be noted that the current grating diffraction efficiency testing device 10 often relies on manual adjustment of the position of the optical power meter 3, which has low adjustment efficiency and poor test accuracy. Based on this, the grating diffraction efficiency testing device 10 in the present application is provided with a first rotating device 7 and a second rotating device 8, the first rotating device 7 is used to drive the grating 4 to rotate, and the second rotating device 8 is used to drive the optical power meter 3 to rotate. It should be noted that the rotation centers of the first rotating device 7 and the second rotating device 8 are consistent. Furthermore, when the grating 4 is driven to rotate by the first rotating device 7, the optical power meter 3 rotates following the grating 4 via the second rotating device 8, that is, the position of the optical power meter 3 changes with the position of the grating 4, so that the optical power meter 3 moves to the propagation path of the diffracted light 41, and according to the automatic optical power collection program, the automatic adjustment of the position of the optical power meter 3 and the automatic collection of the power of the diffracted light 41 are realized, thereby improving the automation degree of the grating 4 diffraction test, thereby improving the test efficiency and accuracy.

[0129] Fig.15 The grating 4 diffraction efficiency test method according to an embodiment of the present invention is applied to the grating diffraction efficiency test system 100 in the third embodiment, such as Fig.15 As shown, the grating 4 diffraction efficiency test method includes:

[0130] Step S101, detecting the power of the diffracted light 41 emitted from the optical device 1;

[0131] Step S102 , determining the diffraction efficiency of the grating 4 according to the power of the diffracted light 41 and the power of the detection light 11 .

[0132] Specifically, the grating 4 diffraction efficiency test method is applied to a grating diffraction efficiency test system 100, which includes a grating diffraction efficiency test device 10, and the grating diffraction efficiency test device 10 includes an optical device 1 and an optical power meter 3. Specifically, when the grating 4 diffraction efficiency test is performed, the light source emits a detection light 11 with different incident angles to the optical device 1. It should be noted that before the detection light 11 is incident on the grating 4, the power of the detection light 11 needs to be detected. In some embodiments of the present application, the detection light 11 can be detected in the light source. A detection device is provided at the optical device 1, and a detection device can also be provided at the outlet of the light source to detect the power of the detection light 11 before the detection light 11 is incident on the optical device 1. When the detection light 11 with different incident angles is incident on the grating 4 through the optical device 1, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 which is emitted from the optical device 1. By adjusting the position of the optical power meter 3, the optical power meter 3 detects the power of the diffracted light 41 emitted from the optical device 1, so as to determine the diffraction efficiency of the grating 4 according to the detected power of the diffracted light 41 and the power of the detection light 11.

[0133] It should be noted that when the detection light 11 is incident on the grating 4 at different angles, the corresponding diffraction light 41 generated by the detection light 11 after diffraction by the grating 4 also has different exit angles. At the same time, when the detection light 11 and the diffraction light 41 are transmitted in the optical device 1, the detection light 11 and the diffraction light 41 will experience power attenuation. If the detection light 11 and the corresponding diffraction light 41 with different incident angles have different optical path lengths in the optical device 1, the detection light 11 and the corresponding diffraction light 41 with different incident angles will experience different degrees of power attenuation when propagating in the optical device 1, which greatly reduces the accuracy of the diffraction efficiency test.

[0134] Based on this, the optical device 1 in the present application ensures that the optical paths of the detection light 11 with different incident angles and the corresponding diffracted light 41 in the optical device 1 are the same, so that the power loss of the detection light 11 with different incident angles when entering the grating 4 through the optical device 1 is the same, and the power loss of the corresponding diffracted light 41 when emitted through the optical device 1 is also the same, thereby ensuring the consistency of the power loss of the detection light 11 in the optical device 1 and the consistency of the power loss of the diffracted light 41 in the optical device 1, which is beneficial to improving the accuracy of the diffraction efficiency test.

[0135] According to the diffraction efficiency testing method of the grating 4 according to the embodiment of the present invention, the power of the diffracted light 41 emitted from the optical device 1 is detected, and the diffraction efficiency of the grating 4 is determined according to the power of the diffracted light 41 and the power of the detection light 11. Since the optical path of the detection light 11 with different incident angles in the optical device 1 is the same, it is ensured that the detection light 11 with different incident angles has the same light loss when propagating in the optical device 1, and since the optical path of different diffracted lights 41 in the optical device 1 is also the same, it is ensured that different diffracted lights 41 have the same light loss when propagating in the optical device 1, which reduces the influence of the light loss in the optical device 1 and is conducive to improving the accuracy of the diffraction efficiency test.

[0136] In some embodiments of the present invention, when the grating 4 is a reflective grating, the diffraction efficiency of the grating 4 is determined according to the power of the diffracted light 41 and the power of the detection light 11, including: obtaining the ratio of the power of the diffracted light 41 to the optical power loss rate of the first prism 2 to obtain a first ratio; obtaining the product of the power of the detection light 11 and the optical power loss rate of the first prism 2 to obtain a second ratio; and determining the diffraction efficiency of the grating 4 according to the first ratio and the second ratio.

[0137] Specifically, Figure 2-Figure 5 As shown, when the grating 4 is a reflective grating, the first prism 2 of the optical device 1 is located on one side of the grating 4. When the light source emits the detection light 11 with different incident angles to the grating 4, the detection light 11 with different incident angles is incident on the grating 4 through the first prism 2. After the detection light 11 is incident on the grating 4, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 and is reflected from the grating 4 to the first prism 2. The diffracted light 41 passes through the first prism 2 and then is emitted from the first prism 2. The optical power meter 3 is used to detect the power of the diffracted light 41 emitted from the first prism 2.

[0138] It should be noted that before obtaining the diffraction efficiency of the grating 4, it is necessary to obtain the optical power loss rate of the first prism 2. Specifically, Fig. 9 As shown, it is necessary to detect the optical power P5 between the interface of the air and the first prism 2 and the optical power P6 at the interface of the first prism 2 and the grating 4 in advance, and obtain the optical power loss rate of the first prism 2 according to the optical power P5 between the interface of the air and the first prism 2 and the optical power P6 at the interface of the first prism 2 and the grating 4. The specific calculation formula is as follows:

[0139] Among them, η 损1 is the optical power loss rate of the first prism 2, P5 is the optical power between the interface between the air and the first prism 2, and P6 is the optical power between the interface between the first prism 2 and the grating 4.

[0140] Further, the diffraction efficiency of the grating 4 is the ratio of the first ratio to the second ratio, the first ratio is the ratio of the power of the diffracted light 41 to the optical power loss rate of the first prism 2, and the second ratio is the product of the power of the detection light 11 and the optical power loss rate of the first prism 2, wherein, Figure 8 As shown, assuming that the power of the diffracted light 41 is P2 and the power of the detection light 11 is P1 as measured by the optical power meter 3, the calculation formula of the diffraction efficiency of the grating 4 is as follows:

[0141] Where η1 is the diffraction efficiency of grating 4, η 损1 is the optical power loss rate of the first prism 2 , P2 is the power of the diffracted light 41 , and P1 is the power of the detection light 11 .

[0142] Therefore, since the attenuation effect of the optical power of the first prism 2 is taken into account during the diffraction efficiency test of the reflective grating, the accuracy of the test is improved.

[0143] It should be noted that when the optical device 1 has a grating substrate 6, the optical power loss of the grating substrate 6 needs to be considered when calculating the diffraction efficiency of the grating 4. Before obtaining the diffraction efficiency of the grating 4, the optical power loss rate of the first prism 2 and the grating substrate 6 needs to be obtained. Specifically, Fig.10 As shown, it is necessary to detect the optical power P5' between the interface between the air and the first prism 2 and the optical power P6' at the interface between the grating substrate 6 and the grating 4 in advance, and obtain the optical power loss rate of the first prism 2 and the grating substrate 6 according to the optical power P5' between the interface between the air and the first prism 2 and the optical power P6' at the interface between the grating substrate 6 and the grating 4. The specific calculation formula is as follows:

[0144] Among them, η' 损1 is the optical power loss rate of the first prism 2 and the grating substrate 6, P5' is the optical power between the interface between the air and the first prism 2, and P6' is the optical power between the interface between the grating substrate 6 and the grating 4.

[0145] Further, the diffraction efficiency of the grating 4 is the ratio of the first ratio to the second ratio, the first ratio is the ratio of the power of the diffracted light 41 to the optical power loss rate of the first prism 2 and the grating substrate 6, and the second ratio is the product of the power of the detection light 11 and the optical power loss rate of the first prism 2 and the grating substrate 6, wherein, Figure 5 As shown, assuming that the power of the diffracted light 41 is P2' and the power of the detection light 11 is P1' as measured by the optical power meter 3, the calculation formula of the diffraction efficiency of the grating 4 is as follows:

[0146] Wherein, η1' is the diffraction efficiency of grating 4, η' 损1is the optical power loss rate of the first prism 2 and the grating substrate 6 , P2 ′ is the power of the diffracted light 41 , and P1 ′ is the power of the detection light 11 .

[0147] Therefore, when the optical device 1 has a grating substrate 6, the attenuation effect of the first prism 2 and the grating substrate 6 on the optical power is taken into account during the diffraction efficiency test of the reflective grating, thereby further improving the accuracy of the test.

[0148] In some embodiments of the present invention, when the grating 4 is a transmission grating, the diffraction efficiency of the grating 4 is determined according to the power of the diffracted light 41 and the power of the detection light 11, including: obtaining the ratio of the power of the diffracted light 41 to the optical power loss rate of the second prism 5 to obtain a third ratio; obtaining the product of the power of the detection light 11 and the optical power loss rate of the first prism 2 to obtain a fourth ratio; and determining the diffraction efficiency of the grating 4 according to the third ratio and the fourth ratio.

[0149] Specifically, Figure 6 and Figure 7 As shown, when the grating 4 is a transmission grating, the first prism 2 and the second prism 5 are respectively located on both sides of the grating 4. When the light source emits detection light 11 with different incident angles to the grating 4, the detection light 11 with different incident angles is incident on the grating 4 through the first prism 2. After the detection light 11 is incident on the grating 4, the detection light 11 is diffracted by the grating 4 to generate diffracted light 41 and is transmitted from the grating 4 to the second prism 5. The diffracted light 41 passes through the second prism 5 and is emitted from the second prism 5. The optical power meter 3 is used to detect the power of the diffracted light 41 emitted from the second prism 5.

[0150] It should be noted that before obtaining the diffraction efficiency of the grating 4, it is necessary to obtain the optical power loss rate of the first prism 2 and the second prism 5. Specifically, Fig. 9 and Fig.11 As shown, it is necessary to detect the optical power P5 between the interface between the air and the first prism 2 and the optical power P6 at the interface between the first prism 2 and the grating 4 in advance, and to detect the optical power P7 between the interface between the air and the second prism 5 and the optical power P8 at the interface between the second prism 5 and the grating 4 in advance. The specific calculation formula for obtaining the optical power loss rate of the first prism 2 according to the optical power P5 between the interface between the air and the first prism 2 and the optical power P6 at the interface between the first prism 2 and the grating 4 is as follows:

[0151] Among them, η 损1 is the optical power loss rate of the first prism 2, P5 is the optical power between the interface between the air and the first prism 2, and P6 is the optical power between the interface between the first prism 2 and the grating 4.

[0152] The specific calculation formula for obtaining the optical power loss rate of the second prism 5 according to the optical power P7 between the interface of the air and the second prism 5 and the optical power P8 at the interface of the second prism 5 and the grating 4 is as follows:

[0153] Among them, η 损2 is the optical power loss rate of the second prism 5, P7 is the optical power between the interface between the air and the second prism 5, and P8 is the optical power between the interface between the second prism 5 and the grating 4.

[0154] Further, the diffraction efficiency of the grating 4 is the ratio of the third ratio to the fourth ratio, the third ratio is the ratio of the power of the diffracted light 41 to the optical power loss rate of the second prism 5, and the fourth ratio is the product of the power of the detection light 11 and the optical power loss rate of the first prism 2, wherein, Figure 6 As shown, assuming that the power of the diffracted light 41 is P4 and the power of the detection light 11 is P3 as measured by the optical power meter 3, the calculation formula of the diffraction efficiency of the grating 4 is as follows:

[0155] Wherein, η2 is the diffraction efficiency of grating 4, η 损1 is the optical power loss rate of the first prism 2, η 损2 is the optical power loss rate of the second prism 5 , P4 is the power of the diffracted light 41 , and P3 is the power of the detection light 11 .

[0156] Therefore, since the attenuation effect of the optical power of the first prism 2 and the second prism 5 is taken into account during the diffraction efficiency test of the transmission grating, the accuracy of the test is improved.

[0157] It should be noted that when the optical device 1 has a grating substrate 6, the loss of optical power caused by the grating substrate 6 needs to be considered when calculating the diffraction efficiency of the grating 4. Figure 7 As shown, when there is a grating substrate 6 between the second prism 5 and the grating 4 and there is no grating substrate 6 between the first prism 2 and the grating 4, as shown in Fig. 9 As shown, it is necessary to detect the optical power P5 between the interface of the air and the first prism 2 and the optical power P6 at the interface of the first prism 2 and the grating 4 in advance, and obtain the optical power loss rate of the first prism 2 according to the optical power P5 between the interface of the air and the first prism 2 and the optical power P6 at the interface of the first prism 2 and the grating 4. The specific calculation formula is as follows:

[0158] Among them, η 损1 is the optical power loss rate of the first prism 2, P5 is the optical power between the interface between the air and the first prism 2, and P6 is the optical power between the interface between the first prism 2 and the grating 4.

[0159] like Fig.12 As shown, the optical power P7' between the interface between the air and the second prism 5 and the optical power P8' at the interface between the grating substrate 6 and the grating 4 are detected in advance, and the specific calculation formula for obtaining the optical power loss rate of the second prism 5 according to the optical power P7' between the interface between the air and the second prism 5 and the optical power P8' at the interface between the second prism 5 and the grating 4 is as follows:

[0160] Among them, η' 损2 is the optical power loss rate of the second prism 5 and the grating substrate 6, P7' is the optical power between the interface between the air and the second prism 5, and P8' is the optical power between the interface between the grating substrate 6 and the grating 4.

[0161] Further, the diffraction efficiency of the grating 4 is the ratio of the third ratio to the fourth ratio, the third ratio is the ratio of the power of the diffracted light 41 to the optical power loss rate of the second prism 5 and the grating substrate 6, and the fourth ratio is the product of the power of the detection light 11 and the optical power loss rate of the first prism 2, wherein, Figure 6 As shown, assuming that the power of the diffracted light 41 is P4' and the power of the detection light 11 is P3 as measured by the optical power meter 3, the calculation formula of the diffraction efficiency of the grating 4 is as follows:

[0162] Wherein, η'2 is the diffraction efficiency of grating 4, η' 损2 is the optical power loss rate of the second prism 5 and the grating substrate 6, η 损1 is the optical power loss rate of the first prism 2 , P4 ′ is the power of the diffracted light 41 , and P3 is the power of the detection light 11 .

[0163] Therefore, when the optical device 1 has a grating substrate 6, the attenuation effect of the first prism 2, the second prism 5 and the grating substrate 6 on the optical power is taken into account during the diffraction efficiency test of the transmission grating, thereby improving the accuracy of the test.

[0164] In some embodiments of the present invention, the method further comprises: determining a rotation angle of the second rotation device 8 according to a rotation angle of the first rotation device 7 .

[0165] Specifically, the current grating diffraction efficiency test device 10 often relies on manual adjustment of the position of the optical power meter 3, which has low adjustment efficiency and poor test accuracy. Based on this, the grating diffraction efficiency test device 10 in the present application is provided with a first rotating device 7 and a second rotating device 8, the first rotating device 7 is used to drive the grating 4 to rotate, and the second rotating device 8 is used to drive the optical power meter 3 to rotate. It should be noted that the rotation centers of the first rotating device 7 and the second rotating device 8 are consistent. Further, when the grating 4 is driven to rotate by the first rotating device 7, the optical power meter 3 rotates following the grating 4 via the second rotating device 8, that is, the rotation angle of the second rotating device 8 is determined according to the rotation angle of the first rotating device 7, so that the position of the optical power meter 3 changes with the position of the grating 4, thereby moving the optical power meter 3 to the propagation path of the diffracted light 41, and according to the automatic optical power acquisition program, the automatic adjustment of the position of the optical power meter 3 and the automatic acquisition of the power of the diffracted light 41 are realized, thereby improving the automation degree of the grating 4 diffraction test, thereby improving the test efficiency and accuracy.

[0166] In some embodiments of the present invention, the rotation angle of the second rotating device 8 is determined according to the rotation angle of the first rotating device 7, including: determining the reference grating 4 vector of the grating 4 based on the first reference light vector of the reference detection light 11 in the grating 4 and the second reference light vector of the reference diffraction light 41 corresponding to the reference detection light 11 in the grating 4; when the first rotating device 7 rotates by a preset angle, determining the rotation angle of the second rotating device 8 according to the preset angle, the first reference light vector, the second reference light vector and the reference grating 4 vector.

[0167] Specifically, Fig.16 As shown, when the rotation angle of the second rotating device 8 is determined according to the rotation angle of the first rotating device 7, the first reference light vector a of the reference detection light 11 in the grating 4 is obtained, and the second reference light vector b of the reference diffraction light 41 corresponding to the reference detection light 11 in the grating 4 is obtained at the same time, and the reference grating 4 vector c of the grating 4 is determined according to the first reference light vector a and the second reference light vector b, and when the first rotating device 7 rotates by a preset angle α, the rotation angle of the second rotating device 8 is determined according to the preset angle α, the first reference light vector a, the second reference light vector b and the reference grating 4 vector c.

[0168] Wherein, the rotation angle of the second rotating device 8 is determined according to the preset angle, the first reference light vector, the second reference light vector and the reference grating 4 vector, including: determining the first light vector of the rotated detection light 11 according to the preset angle and the first reference light vector; determining the second light vector of the rotated diffracted light 41 according to the first light vector and the reference grating 4 vector; determining the rotation angle of the second rotating device 8 according to the second light vector and the second reference light vector.

[0169] Specifically, if Fig.16 As shown, when the first rotating device 7 rotates counterclockwise at a preset angle α, the first reference light vector a rotates counterclockwise at a preset angle α to obtain the first light vector d of the rotated detection light 11, and the second light vector e of the rotated diffracted light 41 can be obtained according to the first light vector d and the reference grating 4 vector c. Specifically, the reference grating 4 vector c is translated so that the first light vector d is relatively connected to the reference grating 4 vector c, and the reference grating 4 vector c is projected along the z direction to the reference circle, then the connecting line between the center of the reference circle and the intersection of the reference circle and the reference grating 4 vector c projected along the z direction is the second light vector e, and the angle between the second light vector e and the reference grating 4 vector c is the rotation angle γ that the second rotating device 8 needs to rotate.

[0170] Thus, the optical power meter 3 can follow the second rotating device 8 to automatically move to the propagation path of the diffracted light 41 and perform automatic collection, which is beneficial to improving the test efficiency. Compared with the manual adjustment test, the test accuracy is more accurate.

[0171] In some embodiments of the present invention, the method further includes: obtaining a grating 4 vector of the grating 4 when the diffraction efficiency is maximum; and detecting whether the grating 4 is qualified according to the grating 4 vector. Specifically, before performing the diffraction efficiency test, it is also necessary to detect whether the grating 4 is qualified. Specifically, by obtaining the grating 4 vector of the grating 4 when the diffraction efficiency is maximum, detecting whether the grating 4 is qualified according to the grating 4 vector, if the grating 4 is unqualified, the grating 4 diffraction efficiency test is not performed, and if the grating 4 is qualified, the grating 4 diffraction efficiency test is performed, thereby avoiding the detection of unqualified grating 4 and causing unnecessary detection waste.

[0172] Specifically, obtaining the grating 4 vector of the grating 4 when the diffraction efficiency is maximum includes: obtaining the incident angle of the detection light 11 and the exit angle of the diffraction light 41 when the diffraction efficiency is maximum, and determining the vector of the detection light 11 in the grating 4 according to the incident angle of the detection light 11, determining the vector of the diffraction light 41 in the grating 4 according to the exit angle of the diffraction light 41, and determining the grating 4 vector of the grating 4 according to the vector of the detection light 11 in the grating 4 and the vector of the diffraction light 41 in the grating 4.

[0173] refer to Fig.17 As shown in (a), the incident angle θ of the probe light 11 during design is obtained. s and the emission angle θ of the diffracted light 41 r , obtain the design value based on the vector relationship As the grating 4 rotates, the reference Fig.17 As shown in (b), the incident angle θ of the detection light 11 when the diffraction efficiency is maximum is obtained. p and the emission angle θ of the diffracted light 41 c According to the vector relationship, the vector of the detection light 11 in the grating 4 can be obtained and the vector of the diffracted light 41 in the grating 4 Then we get the raster 4 vector of raster 4 The vector With design value Compare and verify the pass rate of grating 4.

[0174] like Fig.18 As shown, an embodiment of the present invention further provides a controller 200, including: a memory 210, a processor 220, and a program stored in the memory 210 and executable on the processor 220. When the processor 220 executes the program, the above-mentioned grating 4 diffraction efficiency test method is implemented.

[0175] According to the controller 200 of the embodiment of the present invention, through the above-mentioned grating 4 diffraction efficiency test method, since the optical path of the detection light 11 with different incident angles in the optical device 1 is the same, it is ensured that the detection light 11 with different incident angles has the same light loss when propagating in the optical device 1, and since the optical path of different diffracted light 41 in the optical device 1 is also the same, it is ensured that different diffracted light 41 has the same light loss when propagating in the optical device 1, which reduces the influence of light loss in the optical device 1 and is conducive to improving the accuracy of the diffraction efficiency test.

[0176] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable storage medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable storage medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable storage media include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable storage medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0177] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0178] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0179] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0180] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0181] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An optical device, characterized in that: The detection light with different incident angles is incident on the grating through the optical device, and the diffracted light is generated after diffraction by the grating and emitted from the optical device to test the diffraction efficiency of the grating, wherein the detection light with different incident angles and the corresponding diffracted light have the same optical path in the optical device.

2. The optical device according to claim 1, characterized in that The optical device includes a first prism having a first curved portion. Detection light with different incident angles is incident on the grating through the first curved portion, and diffracted by the grating to generate diffracted light that is emitted from the first curved portion. The curvature at each point on the surface of the first curved portion is the same and the center of curvature coincides, and the center of curvature is located on the grating.

3. The optical device according to claim 2, characterized in that: The first curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism.

4. The optical device according to claim 2, characterized in that: The optical device further includes a grating substrate, which is located between the first prism and the grating, and the refractive index of the first prism is the same as the refractive index of the grating substrate.

5. The optical device according to claim 4, characterized in that: The center of curvature is located on a side surface of the grating close to the grating substrate; or, the center of curvature is located on a side surface of the grating away from the grating substrate; or, the center of curvature is located inside the grating.

6. The optical device according to claim 2, characterized in that: The grating is a reflective grating.

7. The optical device according to claim 1, characterized in that: The optical device includes a first prism and a second prism, the first prism has a first curved portion, the second prism has a second curved portion, detection light of different incident angles is incident on the grating through the first curved portion, and is diffracted by the grating to generate diffracted light that is emitted from the second curved portion, wherein the curvature at each surface point of the first curved portion is the same, the curvature at each surface point of the second curved portion is the same, the center of curvature at each surface point of the first curved portion coincides with the center of curvature at each surface point of the second curved portion, and the center of curvature is located on the grating.

8. The optical device according to claim 7, characterized in that: The first curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism, and the second curved surface portion is a curved surface of a cylindrical prism or a curved surface of a spherical prism.

9. The optical device according to claim 7, characterized in that: The optical device further comprises a grating substrate, wherein the grating substrate is located between the grating and the second prism, and the refractive index of the second prism is the same as the refractive index of the grating substrate.

10. The optical device according to claim 9, characterized in that: The center of curvature is located on a side surface of the grating close to the grating substrate; or, the center of curvature is located on a side surface of the grating away from the grating substrate; or, the center of curvature is located inside the grating.

11. The optical device according to claim 7, characterized in that: The grating is a transmission type grating.

12. The optical device according to claim 4 or 9, characterized in that: The refractive index of the grating is different from the refractive index of the grating substrate.

13. The optical device according to claim 1, characterized in that: The grating is a one-dimensional grating or a two-dimensional grating.

14. A grating diffraction efficiency testing device, characterized in that: Comprising the optical device according to any one of claims 1-13.

15. The device according to claim 14, characterized in that The device also includes: An optical power meter is used to detect the power of the diffracted light emitted from the optical device, so as to determine the diffraction efficiency of the grating according to the power of the diffracted light and the power of the detection light.

16. A grating diffraction efficiency testing system, characterized in that: Comprising the grating diffraction efficiency testing device according to claim 15.

17. The system according to claim 16, characterized in that The system further comprises: a first rotating device and a second rotating device, wherein the grating is driven to rotate by the first rotating device, and the optical power meter is driven to rotate by the second rotating device. When the grating is driven to rotate by the first rotating device, the optical power meter rotates following the grating via the second rotating device.

18. A method for testing grating diffraction efficiency, characterized in that: Applied to the grating diffraction efficiency testing system according to claim 17, the method comprises: detecting the power of the diffracted light emitted from the optical device; The diffraction efficiency of the grating is determined according to the power of the diffracted light and the power of the detection light.

19. The method according to claim 18, characterized in that When the grating is a reflective grating, determining the diffraction efficiency of the grating according to the power of the diffracted light and the power of the detection light includes: Obtaining a ratio of the power of the diffracted light to the optical power loss rate of the first prism to obtain a first ratio; Obtaining the product of the power of the detection light and the optical power loss rate of the first prism to obtain a second ratio; The diffraction efficiency of the grating is determined according to the first ratio and the second ratio.

20. The method according to claim 18, characterized in that When the grating is a transmission type grating, determining the diffraction efficiency of the grating according to the power of the diffracted light and the power of the detection light comprises: Obtaining a ratio of the power of the diffracted light to the optical power loss rate of the second prism to obtain a third ratio; Obtaining the product of the power of the detection light and the optical power loss rate of the first prism to obtain a fourth ratio; The diffraction efficiency of the grating is determined according to the third ratio and the fourth ratio.

21. The method according to claim 18, characterized in that The method further comprises: The rotation angle of the second rotation device is determined according to the rotation angle of the first rotation device.

22. The method according to claim 21, characterized in that The determining the rotation angle of the second rotating device according to the rotation angle of the first rotating device comprises: Determine a reference grating vector of the grating based on a first reference light vector of the reference detection light in the grating and a second reference light vector of the reference diffracted light corresponding to the reference detection light in the grating; When the first rotating device rotates by a preset angle, the rotation angle of the second rotating device is determined according to the preset angle, the first reference light vector, the second reference light vector and the reference grating vector.

23. The method according to claim 22, characterized in that The step of determining the rotation angle of the second rotating device according to the preset angle, the first reference light vector, the second reference light vector and the reference grating vector comprises: Determining a first light vector of the detection light after rotation according to the preset angle and the first reference light vector; Determining a second light vector of the diffracted light after rotation according to the first light vector and the reference grating vector; The rotation angle of the second rotating device is determined according to the second light vector and the second reference light vector.

24. The method according to claim 18, characterized in that The method further comprises: Acquire a grating vector of the grating when the diffraction efficiency is maximum; Whether the grating is qualified is detected according to the grating vector.

25. A controller, characterized in that: include: A memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, the grating diffraction efficiency testing method according to any one of claims 18 to 24 is implemented.

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