A detection system and optical power adjustment method

Abstract

The application provides a detection system and a light power adjustment method. The detection system can include an illumination module and a first detection device, and a light splitting module and a first power adjustment module between the illumination module and the first detection device. The light splitting module is used for periodically switching a working mode. When the working mode is a light transmission mode, an illumination light beam passes through the light splitting module and the first power adjustment module to enter the first detection device. When the working mode is a reflection mode, the illumination light beam is reflected by the light splitting module to enter a light power detection module. The light power detection module is used for detecting the light power of the entering light beam to obtain an actual light power. The first power adjustment module is used for adjusting the power of the light beam passing through the first power adjustment module when the actual light power exceeds a preset range. The illumination light beam is used for full light illumination in an actual illumination process, so that the illumination effect is ensured. The full light light power detection is performed in the gap of the actual illumination of the illumination light beam, so that the accurate light power detection and adjustment are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microscopic imaging, in particular to a detection system and a light power adjustment method. BACKGROUND

[0002] Currently, a detection device can be used to detect a to-be-detected surface. During the detection process, an illumination module needs to provide an illumination light beam. A high-precision detection device requires high environmental stability and illumination stability. In actual operation, if the intensity of the illumination light beam changes, it is easy to cause inaccurate detection results and reduced detection precision, thereby affecting the stability and measurement precision of the detection device.

[0003] In the current detection method for the intensity of the illumination light beam, a light splitting module is usually used to split the illumination light beam into two parts. One part enters the detection device for illumination, and the other part enters the light intensity detection device for light detection. In this way, light detection and detection device illumination can be performed simultaneously. However, after the illumination light beam is split, the light intensity is reduced, thereby affecting the illumination effect of the detection device. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a detection system and a light power adjustment method, which can realize full-light illumination and full-light intensity detection, ensure the illumination stability of the detection system, and ensure the stability and measurement precision of the system.

[0005] The specific scheme is as follows:

[0006] In one aspect, the present application provides a detection system, comprising:

[0007] an illumination module, configured to provide an illumination light beam;

[0008] a first detection device, configured to detect a first to-be-detected surface to obtain a first detection signal;

[0009] a light splitting module and a first power adjustment module between the illumination module and the first detection device, the light splitting module being configured to periodically switch a working mode, when the working mode is a light transmission mode, the illumination light beam transmits through the light splitting module and the first power adjustment module to enter the first detection device, when the working mode is a reflection mode, the illumination light beam is reflected by the light splitting module to enter a light power detection module; the light power detection module is configured to detect the light power of the entering light beam to obtain an actual light power, and the first power adjustment module is configured to adjust the light power of the light beam that transmits through the first power adjustment module when the actual light power exceeds a preset range.

[0010] Optionally, the beam splitting module includes a semi-transparent and semi-reflective module, which includes a light transmission path and a reflective surface. The light transmission path includes a first surface and a second surface. The material between the first surface and the second surface is transparent. The light transmission path and the reflective surface periodically switch to the propagation path of the illumination beam, so that the semi-transparent and semi-reflective module periodically switches its working mode.

[0011] When the light transmission path is switched to the propagation path of the illumination beam, the operating mode is the light transmission mode; when the reflective surface is switched to the propagation path of the illumination beam, the operating mode is the reflection mode.

[0012] Optionally, the semi-transparent and semi-reflective module rotates at a preset rate to periodically switch the light transmission path and the reflective surface to the propagation path of the illumination beam.

[0013] Optionally, the rotation axis of the semi-transparent and semi-reflective module is parallel to and does not coincide with the propagation path of the illumination beam. The semi-transparent and semi-reflective module includes a first part and a second part in a plane perpendicular to the rotation axis. The first part has a light-transmitting path, and the surface of the second part facing the illumination module is a reflective surface. The angle between the emitting surface and the rotation axis is less than 90°. When the semi-transparent and semi-reflective module rotates around the rotation axis, the first part and the second part alternately switch to the propagation path of the illumination beam.

[0014] Optionally, the rotation axis of the semi-transparent and semi-reflective module is perpendicular to the propagation direction of the illumination beam, and the semi-transparent and semi-reflective module has a first surface, a second surface, a third surface, and a fourth surface parallel to the rotation axis; the first surface and the second surface are opposite surfaces; the third surface and the fourth surface are opposite surfaces and are reflective surfaces.

[0015] Optionally, the first surface and the second surface are arranged in parallel, the angle between the third surface and the first surface is equal to the angle between the third surface and the second surface, and the third surface and the fourth surface are not parallel.

[0016] Optionally, the rotational speed of the semi-transparent and semi-reflective module is such that a single sampling by the first detection device corresponds to at least one transmission mode and one reflection mode.

[0017] Optionally, the system further includes:

[0018] The second detection device is used to detect the second surface to be tested and obtain a second detection signal;

[0019] A total beam splitter is configured to split the illumination beam into a first beam and a second beam, the first beam enters the first detection device, and the second beam enters the second detection device.

[0020] Optionally, the first detection device comprises a first reference mirror, a first beam expander, a first beam splitter, and a first detector. The first beam is reflected by the first beam splitter and then transmitted through the first beam expander to the first reference mirror. Part of the light transmitted through the first reference mirror is reflected by a first test surface outside the first reference mirror and away from the first beam expander to form a first reflected beam. The first reflected beam passes through the first reference mirror, the first beam expander, and the first beam splitter to reach the first detector. Part of the light reflected by the first reference mirror forms a second reflected beam, which passes through the first beam expander and the first beam splitter to reach the first detector. The first detector is configured to obtain interference information of the first reflected beam and the second reflected beam as the first detection signal.

[0021] The second detection device comprises a second reference mirror, a second beam expander, a second beam splitter, and a second detector. The second beam is reflected by the second beam splitter and then transmitted through the second beam expander to the second reference mirror. Part of the light transmitted through the second reference mirror is reflected by a second test surface outside the second reference mirror and away from the second beam expander to form a third reflected beam. The third reflected beam passes through the second reference mirror, the second beam expander, and the second beam splitter to reach the second detector. Part of the light reflected by the second reference mirror forms a fourth reflected beam, which passes through the second beam expander and the second beam splitter to reach the second detector. The second detector is configured to obtain interference information of the third reflected beam and the fourth reflected beam as the second detection signal.

[0022] Optionally, the system further comprises:

[0023] A second power adjustment module between the total beam splitter and the second detection device. The second power adjustment module is configured to adjust the optical power of the light beam transmitted through the second power adjustment module when the actual optical power exceeds a preset range.

[0024] Optionally, the illumination beam is linearly polarized light, and the first power adjustment module and the second power adjustment module comprise a polarizer. The polarization direction of the polarizer is adjusted to adjust the optical power of the light beam transmitted through the polarizer.

[0025] Optionally, the first surface and the second surface are surfaces of different sides of the same object to be measured, the first detection device further comprises a first quarter wave plate between the first beam expander and the first beam splitter, the second detection device further comprises a second quarter wave plate between the second beam expander and the second beam splitter, the fast axis directions of the first quarter wave plate and the second quarter wave plate are orthogonal, and the first beam splitter and the second beam splitter are polarization beam splitters.

[0026] Optionally, the system further comprises:

[0027] a total collimator between the illumination module and the total beam splitter;

[0028] a first condenser and a first optical fiber between the total beam splitter and the first detection device;

[0029] a second condenser and a second optical fiber between the total beam splitter and the second detection device.

[0030] Optionally, the system further comprises:

[0031] a mirror between the beam splitting module and the optical power detection module, for reflecting the light beam reflected by the beam splitting module to the optical power detection module.

[0032] In another aspect, the embodiments of the present application also provide an optical power adjustment method applied to the detection system, the method comprising:

[0033] adjusting the optical power of the light beam passing through the first power adjustment module when the actual optical power is out of the preset range.

[0034] Optionally, the adjusting the optical power of the light beam passing through the first power adjustment module when the actual optical power is out of the preset range comprises:

[0035] increasing the optical power of the light beam passing through the first power adjustment module when the actual optical power is less than the lower limit of the preset range.

[0036] Optionally, the illumination light beam is linearly polarized light, the first power adjustment module comprises a polarizer, and the adjusting the optical power of the light beam passing through the first power adjustment module when the actual optical power is out of the preset range comprises:

[0037] adjusting the polarization direction of the polarizer to adjust the optical power of the light beam passing through the first power adjustment module when the actual optical power is out of the preset range.

[0038] The embodiment of the present application provides a detection system and a light power adjustment method. The detection system can comprise an illumination module, a first detection device, a light splitting module and a first power adjustment module between the illumination module and the first detection device. The light splitting module is used for periodically switching a working mode. When the working mode is a light transmission mode, an illumination light beam transmits through the light splitting module and the first power adjustment module to enter the first detection device. When the working mode is a reflection mode, the illumination light beam is reflected by the light splitting module to enter a light power detection module. The light power detection module is used for detecting the light power of the entering light beam to obtain an actual light power. The first power adjustment module is used for adjusting the power of the light beam transmitting through the first power adjustment module when the actual light power exceeds a preset range. In this way, the working mode of the light splitting module can be switched to respectively realize actual illumination of the illumination light beam and light power detection in different working modes, that is, the illumination light beam is illuminated by full light in the actual illumination process, the illumination effect is ensured, the light power detection of full light is performed in the gap of the actual illumination of the illumination light beam, the accurate light power detection is realized, and then the accurate adjustment of the light power is realized. In the case that the working mode is rapidly switched, the actual illumination of the illumination light beam is less affected or even not affected, and the light power detection can be performed without affecting the detection of the detection device on the measured surface. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0040] Figure 1 A structure schematic diagram of a detection system provided by the embodiment of the present application is shown;

[0041] Figure 2 And Figure 3 A working schematic diagram of a light splitting module provided by the embodiment of the present application is shown;

[0042] Figure 4 And Figure 5 A working schematic diagram of another light splitting module provided by the embodiment of the present application is shown;

[0043] Figure 6 A structure schematic diagram of another detection system provided by the embodiment of the present application is shown;

[0044] Figure 7 A schematic diagram of a first interference image provided by the embodiment of the present application is shown. DETAILED DESCRIPTION

[0045] In order to make the above objectives, characteristics and advantages of the present application more apparent, a detailed description of the specific embodiments of the present application will be given below with reference to the accompanying drawings.

[0046] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0047] Secondly, the present application is described in detail in combination with the schematic diagram, in the detailed description of the embodiments of the present application, in order to facilitate the description, the cross-sectional view of the device structure will be partially enlarged without the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present application here. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in actual manufacture.

[0048] In order to facilitate understanding, the detection system and the optical power adjustment method provided by the embodiments of the present application will be described in detail below in combination with the accompanying drawings.

[0049] Reference Figure 1 As shown in the figure, the structure schematic diagram of the detection system provided by the embodiments of the present application, the detection system includes an illumination module 100, a first detection device 300, and a light splitting module 204 and a first power adjustment module 207 between the illumination module 100 and the first detection device 300.

[0050] The illumination module 100 is used to provide an illumination beam, so as to illuminate the field of view of the first detection device 300, the illumination module 100 can be a laser for example. The illumination beam is determined according to the type of the first detection device 300, if the first detection device 300 is an interferometer, the illumination beam is usually monochromatic light or composite light of multiple wavelengths, if the first detection device 300 is other instrument, the illumination beam can be composite light of multiple wavelengths.

[0051] The first detection device 300 is used to detect the first surface to be detected to obtain a first detection signal, the first detection device 300 can be an interferometer, or other detection device. When the detection accuracy of the first detection device 300 is high, the illumination module 100 needs to provide a stable illumination beam, for example, the optical power of the illumination beam entering the first detection device 300 needs to be within a preset range.

[0052] The light splitting module 204 is used to periodically switch the working mode, and the optical power detection module 206 is used to detect the actual optical power of the incoming light beam. When the working mode is the light transmission mode, the light splitting module 204 can transmit the light beam, and then the illumination light beam transmits through the light splitting module 204 and the first power adjustment module 207 to enter the first detection device 300, that is, the illumination light beam illuminates the field of view of the first detection device 300. When the working mode is the reflection mode, the illumination light beam is reflected by the light splitting module 204 to enter the optical power detection module 206, so that the optical power detection module 206 detects the actual optical power of the incoming light beam.

[0053] The first power adjustment module 207 is used to adjust the power of the light beam that transmits through the first power adjustment module 207 when the actual optical power exceeds the preset range. In this way, the working mode of the light splitting module 204 can be switched to realize the actual illumination of the illumination light beam and the optical power detection in different working modes, respectively. That is, the illumination light beam is fully illuminated during the actual illumination to ensure the illumination effect, and the optical power detection is performed during the interval of the actual illumination of the illumination light beam. Therefore, the full illumination and the full detection are combined to realize the accurate optical power detection and the accurate adjustment of the optical power. In addition, the working mode is switched rapidly, and the actual illumination of the illumination light beam is less affected or even not affected. Therefore, the optical power detection can be performed without affecting the detection of the surface to be detected by the detection device.

[0054] The light splitting module 204 can include a semi-transparent and semi-reflective module. The semi-transparent and semi-reflective module includes a light transmission path and a reflection surface. The light transmission path includes a first surface and a second surface, and the material between the first surface and the second surface is transparent. The light transmission path and the reflection surface are periodically switched to the propagation path of the illumination light beam to periodically switch the working mode of the semi-transparent and semi-reflective module. When the light transmission path is switched to the propagation path of the illumination light beam, the corresponding working mode is the light transmission mode, one of the first surface and the second surface is the incident surface of the illumination light beam, and the other is the exit surface of the illumination light beam. When the reflection surface is switched to the propagation path of the illumination light beam, the working mode is the reflection mode. The illumination light beam can be intercepted outside the semi-transparent and semi-reflective module by the reflection surface, or the illumination light beam can be reflected by the reflection surface to the outside of the semi-transparent and semi-reflective module. In this way, the working mode of the light splitting module 204 can be switched by the structure of the semi-transparent and semi-reflective module.

[0055] The light transmission passage and the reflecting surface can be switched to the propagation path of the illumination light beam in a translational manner or in a rotational manner. As an example, the semi-transparent and semi-reflective module rotates at a preset rate to periodically switch the light transmission passage and the reflecting surface to the propagation path of the illumination light beam, to periodically switch the working mode and to periodically detect the optical power. The rotational manner is conducive to high-speed switching of the high-speed working mode. Specifically, the semi-transparent and semi-reflective module can be driven to rotate by a high-speed rotating motor.

[0056] As a possible implementation, the rotation axis of the semi-transparent and semi-reflective module is parallel to and does not coincide with the propagation path of the illumination light beam. The rotation plane of the semi-transparent and semi-reflective module can be perpendicular to or at an angle to the propagation path of the illumination light beam. The semi-transparent and semi-reflective module includes a first part and a second part in a plane perpendicular to the rotation axis. The first part has a light transmission passage, and the second part has a reflecting surface facing the side surface of the illumination module 100. The angle between the reflecting surface and the rotation axis is less than 90°, so that the illumination light beam irradiated onto the reflecting surface is reflected out of the original light path to the optical power detection module 206, instead of returning along the original light path. By rotating the semi-transparent and semi-reflective module around the rotation axis, the first part and the second part are alternately switched to the propagation path of the illumination light beam, to switch the working mode of the semi-transparent and semi-reflective module.

[0057] The rotation axis of the semi-transparent and semi-reflective module can be located on the boundary between the first part and the second part. The semi-transparent and semi-reflective module can be circular or have other shapes. The first part is provided with an anti-reflection film. The first part and the second part can each include one or multiple. Multiple first parts and multiple second parts are alternately arranged in a circumferential direction on the side surface of the semi-transparent and semi-reflective module facing the illumination module, so that one rotation of the semi-transparent and semi-reflective module can realize multiple switching of the working mode. For example, the side surface of the semi-transparent and semi-reflective module facing the illumination module includes two first parts and two second parts in a circumferential direction, forming a cross shape. The center of the cross shape is the rotation axis of the semi-transparent and semi-reflective module. The two sides of one first part are adjacent to two second parts, respectively. The two sides of one second part are adjacent to two first parts, respectively. The first part and the second part can have the same area or different areas on the side surface of the semi-transparent and semi-reflective module facing the illumination module.

[0058] Reference Figure 2 and Figure 3 As shown in FIGS. 1 to 3, the present application provides a light splitting module. The light splitting module includes a first part 204A and a second part 204B, indicates that the surface is a transmission surface, indicates that the surface is a reflecting surface. The dashed line indicates the position of the rotation axis, which is also the boundary between the first part 204A and the second part 204B. Among them, Figure 2The middle illumination light beam irradiates to the first part 204A, and the illumination light beam continues to propagate forward through the light splitting module, Figure 3 The middle illumination light beam irradiates to the second part 204B, and then is reflected to the optical power detection module 206.

[0059] Specifically, the first part 204A can have a first surface and a second surface which are parallel and opposite, the reflecting surface in the second part can be connected with the first surface and forms an obtuse angle, and the second part 204B further includes a back surface connected with the second surface, and the back surface and the second surface can have the same extension direction. In the reflecting surface, each point having the same distance from the rotation axis can have the same thickness, so that the illumination light beam is reflected to the same direction during the rotation, and thus the optical power detection module 206 can continuously acquire the illumination light beam for detection when the illumination light beam continuously irradiates the second part 204B.

[0060] As another possible implementation, the rotation axis of the semi-transparent and semi-reflective module is perpendicular to the propagation direction of the illumination light beam, the semi-transparent and semi-reflective module has a first surface, a second surface, a third surface and a fourth surface which are parallel to the rotation axis, the first surface and the second surface and the material therebetween constitute a light transmission path, the third surface and the fourth surface are reflecting surfaces, and the plurality of surfaces constitute a multi-faceted prism. The first surface and the second surface can be opposite surfaces, so that the illumination light beam irradiates from the first surface to the second surface or from the second surface to the first surface; the third surface and the fourth surface can be opposite surfaces. The first surface, the second surface, the third surface and the fourth surface are switched to the propagation path of the illumination light beam in a certain order to realize the switching of the working mode of the semi-transparent and semi-reflective module. The rotation axis of the semi-transparent and semi-reflective module can be located at the center position of the columnar structure constituted by the first surface, the second surface, the third surface and the fourth surface, and the rotation axis can be located in any direction in the plane perpendicular to the propagation direction of the illumination light beam, for example, can be horizontal or vertical, etc. The first surface and the second surface can be provided with an anti-reflection film.

[0061] Reference Figure 4 and Figure 5 As shown in FIGS. 1, 2 and 3, the light splitting module provided by the embodiment of the present application includes a first surface S3, a second surface S4, a third surface S1 and a fourth surface S2, indicates that the surface is a transmission surface, indicates that the surface is a reflecting surface, and the rotation axis is perpendicular to the paper. Wherein, Figure 4 The middle illumination light beam irradiates to the first surface S3 and is transmitted to the second surface S4, and the illumination light beam continues to propagate forward through the light splitting module, Figure 5 The middle illumination light beam irradiates to the third surface S1, and then is reflected to the optical power detection module 206.

[0062] The first surface S3 and the second surface S4 can be arranged in parallel, the included angle between the third surface S1 and the first surface S3 is equal to the included angle between the third surface S1 and the second surface S4, the third surface S1 and the fourth surface S2 are not parallel, so that the columnar structure formed by the first surface S3, the second surface S4, the third surface S1 and the fourth surface S2 is a trapezoidal columnar structure, and when the third surface S1 and the fourth surface S2 switch to the propagation path of the illumination light beam, the reflection direction of the illumination light beam reflected by the third surface S1 or the fourth surface S2 changes constantly during the rotation process, and the duration of the reflected light beam continuously irradiating the optical power detection module 206 is related to the rotation speed of the semi-transmission and semi-reflection module.

[0063] The greater the number of revolutions per second of the semi-transmission and semi-reflection module, the faster the switching speed of the working mode, and the shorter the duration of a single working mode. In the case that the working mode is switched at least twice during each sampling period of the first detection device 300, each sampling corresponds to at least one transmission mode and one reflection mode, so that the optical power detection does not affect the normal operation of the first detection device 300, and the optical power detection and sample detection are realized, that is, the full light detection is considered in the sampling gap without affecting the sampling, and the full light illumination and full light detection are realized at the same time from a macro perspective. In the case that the semi-transmission and semi-reflection module rotates one revolution to realize twice working mode switching (refer to Figure 2 and Figure 3 ), the number of revolutions per second of the semi-transmission and semi-reflection module can be greater than or equal to the sampling frequency f of the first detection device 300 per second. The sampling frequency f of the first detection device 300 per second is denoted as f, and the number of revolutions per second of the semi-transmission and semi-reflection module is greater than or equal to the sampling frequency f of the first detection device 300. The unit of the rotation speed v of the semi-transmission and semi-reflection module is rpm, so v≥60*f. Taking the sampling frequency f of 54Hz as an example, the rotation speed v is greater than or equal to 3240rpm. In the case that the semi-transmission and semi-reflection module rotates one revolution to realize four times working mode switching (refer to Figure 4 and Figure 5 ), the number of revolutions per second of the semi-transmission and semi-reflection module can be greater than or equal to half of the sampling frequency f of the first detection device 300 per second.

[0064] The mirror 205 can be arranged between the light splitting module 204 and the optical power detection module 206, for reflecting the light beam reflected by the light splitting module 204 to the optical power detection module 206, so as to realize the turning of the light path and meet the demand of the intermediate visual space layout.

[0065] In the embodiment of the application, the illumination light beam can simultaneously provide illumination for multiple detection devices, that is, the detection system can further include a second detection device 500 and a total light splitter 202. Refer to Figure 6As shown, the structure of another detection system provided by the embodiment of the present application is shown, the second detection device 500 is used for detecting the second surface to be detected to obtain a second detection signal, the total beam splitter 202 is used for splitting the illumination beam into a first beam and a second beam, the first beam enters the first detection device 300, and is used for illuminating the first detection device 300, the second beam enters the second detection device 500, and is used for illuminating the second detection device 500, so that the detection efficiency can be improved. In addition, the reflection module 203 can also be included to make the propagation path of the second beam be bent.

[0066] In the presence of the total beam splitter 202, the first power adjustment module 207 can be arranged between the total beam splitter 202 and the illumination module 100, and is used for adjusting the total optical power of the first beam and the second beam. In addition, the first power adjustment module 207 can be arranged between the total beam splitter 202 and the first detection device 300, and is used for adjusting the optical power of the first beam, so as to improve the pertinence of the first optical power adjustment. Corresponding to the optical path of the first detection device 300, the second detection device 500 and the total beam splitter 202 can also be provided with the second power adjustment module 208, and the second power adjustment module 208 is used for adjusting the optical power of the light beam passing through the second power adjustment module 208 when the actual optical power exceeds the preset range, so that the second detection device 500 can work under normal illumination.

[0067] The system can also include the total collimator 201 between the illumination module 100 and the total beam splitter 202, which is used for collimating the illumination beam emitted by the illumination module 100, and improving the energy concentration degree of the light beam. The system can also include the first condenser lens 209 and the first optical fiber 214 between the total beam splitter 202 and the first detection device 300, and the second condenser lens 210 and the second optical fiber 213 between the total beam splitter 202 and the second detection device 500. The first condenser lens 209 and the second condenser lens 210 are used for condensing the light beam, and the first optical fiber 214 and the second optical fiber 213 are used for transmitting the light beam. The first beam enters the first optical fiber 214 through the first optical fiber receiving end 212, and the second beam enters the second optical fiber 213 through the second optical fiber receiving end 211. The first optical fiber 214 and the second optical fiber 213 have the function of light homogenization.

[0068] Reference Figure 6 As shown, the illumination module 100 outputs an illumination beam, and the illumination beam becomes a collimated light after passing through the total collimator 201 and is incident on the total beam splitter 202. The total beam splitter 202 splits the collimated light into a first beam and a second beam, wherein the first beam is transmitted through the total beam splitter 202, and the second beam is reflected by the total beam splitter 202.

[0069] The first light beam is transmitted through the total beam splitter 202 and is incident on the beam splitting module 204. When the beam splitting module 204 works in the transmission mode, the first light beam is incident on the first power adjustment module 207, and then is coupled to the first fiber receiving end 212 through the first converging lens 209. The first light beam is guided into the first detection device 300 through the first optical fiber 214 and is used as the illumination light to irradiate one side surface of the object 400. When the beam splitting module 204 works in the reflection mode, the first light beam is reflected by the reflection surface with a certain inclination angle to the light path, is reflected to the reflecting mirror 205, and then is reflected to the optical power detection module 206. In this way, the optical power detection module 206 and the first power adjustment module 207 are added in the detection system. Through the cooperation of the software and hardware control calculation, the light output by the illumination module 100 is periodically detected and compensated, the stable interference system is maintained, the illumination quality of the system is ensured, and the dynamic compensation control unit is added at the same time to feedback compensate the attenuation of the laser, further improve the system adaptability, and improve the measurement accuracy.

[0070] The second light beam is reflected by the total beam splitter 202, is reflected to the reflecting module 203, is incident on the second power adjustment module 208, is coupled to the second fiber receiving end 211 through the second converging lens 210, and then is guided into the second detection device 500 through the second optical fiber 213 and is used as the illumination light to irradiate the other side surface of the object 400. In this way, the light power of the illumination module 100 can be detected whether it is stable while the double-side interference patterns of the object 400 are collected without losing the light power, and the second power adjustment module 208 is compensated in time when it is unstable.

[0071] The first detection device 300 can be an interferometer, for example, a Fizeau interferometer. The first detection device 300 includes a first reference mirror 304, a first beam expander 303, a first beam splitter 301, and a first detector 306. The first light beam is reflected by the first beam splitter 301 and is transmitted through the first beam expander 303 to irradiate the first reference mirror 304. The part of the first light beam that transmits through the first reference mirror 304 irradiates the first object surface on the side away from the first beam expander 303 to reflect the first reflected light beam. The first reflected light beam passes through the first reference mirror 304, the first beam expander 303, and the first beam splitter 301 to reach the first detector 306. The part of the first light beam reflected by the first reference mirror 304 is the second reflected light beam, which passes through the first beam expander 303 and the first beam splitter 301 to reach the first detector 306. The first detector 306 is used to obtain the interference information of the first reflected light beam and the second reflected light beam as the first detection signal.

[0072] The second detection device 500 can be an interferometer, for example, a Fizeau interferometer. The second detection device 500 includes a second reference mirror 310, a second beam expander 309, a second beam splitter 307, and a second detector 312. The second light beam is reflected by the second beam splitter 307 and then transmitted through the second beam expander 309 to the second reference mirror 310. Part of the second light beam transmitted through the second reference mirror 310 is reflected by the second reference mirror 310 to a second surface to be detected on the side of the second beam expander 309, and then the third reflected light beam is obtained. The third reflected light beam passes through the second reference mirror 310, the second beam expander 309, and the second beam splitter 307 to the second detector 312. Part of the second light beam reflected by the second reference mirror 310 is the fourth reflected light beam, which passes through the second beam expander 309 and the second beam splitter 307 to the second detector 312. The second detector 312 is configured to obtain interference information of the third reflected light beam and the fourth reflected light beam as a second detection signal.

[0073] The illumination light beam emitted by the illumination module 100 can be linearly polarized light. The first power adjustment module 207 and the second power adjustment module 208 include polarizing plates. The polarization direction of the polarizing plate is adjusted to adjust the optical power of the light beam of the polarized light. That is, the polarization direction of the polarizing plate of the first power adjustment module 207 is adjusted to adjust the optical power of the first light beam, and the polarization direction of the polarizing plate of the second power adjustment module 208 is adjusted to adjust the optical power of the second light beam. When the first detection device 300 and the second detection device 500 are interferometers, linearly polarized light is beneficial to improve the realization of more obvious interference phenomena and obtain high-contrast interference patterns.

[0074] The first surface to be detected and the second surface to be detected are surfaces on different sides of the same object to be detected 400. The first detection device 300 further includes a first quarter-wave plate 302 between the first beam expander 303 and the first beam splitter 301, which is configured to convert linearly polarized light into circularly polarized light. The second detection device 500 further includes a second quarter-wave plate 308 between the second beam expander 309 and the second beam splitter 307, which is configured to convert linearly polarized light into circularly polarized light. The fast axis directions of the first quarter-wave plate 302 and the second quarter-wave plate 308 are orthogonal. The first beam splitter 301 and the second beam splitter 307 are polarization beam splitters, which realize the separate detection of the first surface to be detected and the second surface to be detected.

[0075] Reference Figure 6As shown, in the first detection device 300, the first light beam is reflected by the first beam splitter 301 into the first detection light path, and then forms circularly polarized light by the first quarter wave plate 302. The circularly polarized light is expanded by the first beam expander 303, and then the expanded collimated light is incident on the first measurement surface of the object 400 after passing through the first reference mirror 304. The light reflected by the first measurement surface and the light reflected by the first reference mirror 304 interfere with each other, are transmitted by the first beam splitter 301, and then are imaged onto the first detector 306 by the first relay lens group 305. Similarly, in the second detection device 500, the second light beam is reflected by the second beam splitter 307 into the second detection light path, and then forms circularly polarized light by the second quarter wave plate 308. The circularly polarized light is expanded by the second beam expander 309, and then the expanded collimated light is incident on the second measurement surface of the object 400 after passing through the second reference mirror 310. The light reflected by the second measurement surface and the light reflected by the second reference mirror 310 interfere with each other, are transmitted by the second beam splitter 307, and then are imaged onto the second detector 312 by the second relay lens group 311.

[0076] The first beam splitter 301 and the second beam splitter 307 are polarizing beam splitters, which can reflect all the incident linearly polarized light s into the interference light path. The fast axis directions of the first quarter wave plate 302 and the second quarter wave plate 308 are orthogonal, for example, the fast axis directions are + / - 45° with respect to the optical axis directions, so that the light s passing through the first quarter wave plate 302 and the second quarter wave plate 308 becomes left-handed circularly polarized light and right-handed circularly polarized light (both are circularly polarized light). In this way, the circularly polarized light reflected by the first measurement surface and the first reference mirror on the side of the first quarter wave plate 302 is transmitted from the first beam splitter after passing through the first quarter wave plate 302 again, and forms p light whose polarization direction is orthogonal to that of the s light incident from the first beam splitter; similarly, the circularly polarized light reflected by the second measurement surface and the second reference mirror on the side of the second quarter wave plate 308 is transmitted from the second beam splitter after passing through the second quarter wave plate 308 again, and forms p light whose polarization direction is orthogonal to that of the s light incident from the second beam splitter.

[0077] Conversely, the s light incident from the first beam splitter 301 forms circularly polarized light after passing through the first quarter-wave plate 302, and then transmits through the object to be measured or is incident from the surroundings of the object to be measured to the opposite light path, and then, after passing through the second quarter-wave plate 308, the s light polarized direction is maintained and the light is reflected out of the light path by the second beam splitter, and will not become p light to enter the second detector; correspondingly, the s light incident from the second beam splitter forms circularly polarized light after passing through the second quarter-wave plate 308, and then transmits through the object to be measured or is incident from the surroundings of the object to be measured to the opposite light path, and then, after passing through the first quarter-wave plate 302, the s light polarized direction is maintained and the light is reflected out of the light path by the first beam splitter, and will not become p light to enter the first detector. In this way, the mutual interference of the two interference light paths can be prevented, and the detection of the two surfaces to be measured can be realized respectively.

[0078] The object to be measured 400 can be a wafer, so that the two side surfaces of the wafer are detected, and such detection requires high environmental and illumination stability to meet the repeatability index within the nanometer level. The illumination module is a key module of the interferometric surface measurement, and provides uniform and speckle-controlled illumination conditions for the Fizeau interferometer. The overall brightness and uniformity of the interference pattern formed by the interference of the reference mirror and the surface of the wafer to be measured have a great influence on the interference fringe contrast. Therefore, it is very important to add a stable and reliable monitoring unit in the illumination light path.

[0079] The embodiment of the present application provides a detection system, which can include an illumination module and a first detection device, and a beam splitting module and a first power adjustment module between the illumination module and the first detection device, the beam splitting module is used for periodically switching a working mode, when the working mode is a transmission mode, an illumination light beam transmits through the beam splitting module and the first power adjustment module to enter the first detection device, when the working mode is a reflection mode, the illumination light beam is reflected by the beam splitting module to enter a light power detection module, the light power detection module is used for detecting the light power of the entering light beam to obtain an actual light power, and the first power adjustment module is used for adjusting the power of the light beam transmitting through the first power adjustment module when the actual light power exceeds a preset range. In this way, the working mode of the beam splitting module can be switched to respectively realize the actual illumination of the illumination light beam and the light power detection in different working modes, that is, the illumination light beam is fully illuminated in the actual illumination process to ensure the illumination effect, and the light power detection is performed in the gap of the actual illumination of the illumination light beam to realize accurate light power detection and accurate adjustment of the light power, and the actual illumination of the illumination light beam is less affected or even not affected in the case of rapid switching of the working mode.

[0080] Based on the detection system provided in the above embodiment, the embodiment of the present application further provides a light power adjustment method, which is applied to the foregoing detection system and can include: adjusting the light power of the light beam transmitting through the first power adjustment module when the actual light power exceeds the preset range to adjust the intensity of the first detection signal.

[0081] In the embodiment, when the actual light power exceeds the preset range, it indicates that the output power of the illumination module decays to an unacceptable range, and the light power of the light beam passing through the first power adjustment module can be adjusted to maintain the stability of the illumination environment in the product life cycle and ensure the measurement accuracy of the stability of the detection system.

[0082] Specifically, when the actual light power is less than the lower limit of the preset range, the light power of the light beam passing through the first power adjustment module can be increased. In a specific implementation, when the actual light power is less than the lower limit of the preset range, the required light power can be determined according to the lower limit of the preset range; and the light power of the light beam passing through the first power adjustment module can be increased according to the required light power, so that the light power of the light beam is increased, the signal quality of the first detection signal is improved, and the detection accuracy is improved. The preset range can be determined according to the historical detection light power, which is saved as a constant in the device to realize light power adjustment.

[0083] Specifically, the illumination light beam is linearly polarized light, and the first power adjustment module includes a polarizer. When the actual light power exceeds the preset range, the polarization direction of the polarizer can be adjusted to adjust the light power of the light beam passing through the first power adjustment module. In a specific implementation, when the actual light power exceeds the preset range, the required polarization direction of the polarizer can be determined according to the required light power; and the polarization direction of the polarizer can be adjusted according to the required polarization direction to increase the light power of the light beam passing through the first power adjustment module. This way can realize accurate control of the light power. The angle between the polarization direction of the incident linearly polarized light and the polarization direction of the polarizer is different, and the transmission rate of the linearly polarized light is different. The angle between the polarization direction of the incident linearly polarized light and the polarization direction of the polarizer can be determined according to the actual light power and the required light power, and then the required polarization direction of the polarizer is determined to realize power adjustment.

[0084] In the case where the required light power remains constant, the required polarization direction has a corresponding relationship with the actual light power. After the actual light power decays, the required polarization direction can be determined according to the corresponding relationship, and then the polarizer is adjusted to compensate the light power to the required light power. That is, in actual work, the polarization direction of the polarizer is usually not parallel to the polarization direction of the illumination light beam to reserve a compensation range for subsequent compensation. In the device debugging stage, the corresponding relationship between different required polarization directions and different actual light powers can be saved in the device for calling.

[0085] Afterwards, if the intensity of the first detection signal meets the preset condition, the adjustment of the optical power of the light beam passing through the first power adjustment module is stopped. That is, the first detection signal can also be acquired, and whether the adjustment of the optical power of the light beam meets the requirement is determined according to the intensity of the first detection signal. If the intensity of the first detection signal meets the preset condition, it indicates that the quality of the first detection signal is high, and thus the adjustment of the optical power of the light beam passing through the first power adjustment module can be stopped. In this way, the adjustment of the optical power can be based on the actual optical power, the intensity of the first detection signal is used as a verification item for the adjustment of the optical power, the quality of the first detection signal is detected at the same time as the optical power, so as to perform dynamic compensation control, the adjustment of the optical power can make the intensity of the first detection signal meet the preset condition, accurate adjustment of the optical power is realized, the system adaptability is improved, the stability of illumination imaging of the detection system is ensured, and the measurement accuracy of the system is ensured.

[0086] Due to high resolution and high accuracy and characteristics, the change of the laser detected by the optical power detector is relatively accurate, and the change of the illumination state can be more intuitively and accurately fed back. However, the illumination fringe required by the interferometer is based on the SNR representation of the interference pattern. If the SNR representation of the interference pattern is directly used to represent the change of the illumination mode, it is not accurate enough. Because there are various disturbance errors in the system, such as test repeatability, vibration, environmental disturbance and the like, which will all affect the numerical change of the SNR. Therefore, the numerical value of the SNR cannot be used to represent the change of the illumination laser or the illumination mode. Therefore, the optical power meter directly representing the change of the laser and the SNR directly representing the interference illumination effect need to be connected, and the influence of the illumination and interference effect is indirectly verified, which can greatly help to maintain stable illumination adjustment.

[0087] When the first detection signal includes the first interference image, if the contrast (SNR) of the first interference image is in a preset contrast range, it indicates that the first interference image can accurately reflect the characteristics of the interference fringes, and it can be considered that the intensity of the first detection signal meets the preset condition, and the adjustment of the optical power of the light beam passing through the first optical power adjustment module can be stopped. The contrast of the first interference image is used as a verification item, which is beneficial to obtaining a first interference image with high quality and improving the detection accuracy. The preset contrast range can be determined according to the contrast of the historical image, which is saved in the device as a constant to realize the verification of the optical power adjustment.

[0088] The first interference image is obtained after the actual optical power, and the first interference image and the actual optical power can be obtained in different sampling periods, and the sampling period interval between the acquisition times of the two is not more than a preset number, so that the first interference image can reflect the adjustment effect of the optical power in a timely manner. In specific implementation, the actual optical power and the interference image in the same sampling period can be saved as a subsequent comparison basis, that is, the optical power and the interference image are synchronously detected, and the dynamic compensation of the optical power is realized accordingly, the stability of system illumination imaging is ensured, and the measurement accuracy of the system is ensured.

[0089] The contrast of the first interference image can be the contrast in a fixed region of the first interference image, which will represent the overall contrast of the first interference image. Referring to Figure 7 As shown in the figure, the contrast in the fixed region 1001 (the region in the rectangular frame formed by white lines) of the first interference image provided by the embodiment of the application is 0.8958.

[0090] In the embodiment of the application, when the detection system comprises the second power adjustment module, the light power of the light beam passing through the second power adjustment module can also be adjusted when the actual light power exceeds the preset range, so as to adjust the intensity of the second detection signal. In addition, if the intensity of the second detection signal meets the preset condition, it means that the quality of the second detection signal is high, and therefore the adjustment of the light power of the light beam passing through the second power adjustment module can be stopped. In this way, the adjustment of the light power can be based on the actual light power, and the intensity of the second detection signal can be used as a verification item for the adjustment of the light power, so that the adjustment of the light power can make the intensity of the second detection signal meet the preset condition, and accurate adjustment of the light power can be realized.

[0091] Specifically, when the actual light power is less than the lower limit of the preset range, the light power of the light beam passing through the second power adjustment module is increased. In specific implementation, when the actual light power is less than the lower limit of the preset range, the required light power of the second light beam can be determined according to the lower limit of the preset range; and the light power of the light beam passing through the second power adjustment module is increased according to the required light power of the second light beam, so that the light power of the second light beam is increased, the signal quality of the second detection signal is improved, and the detection accuracy is improved.

[0092] Specifically, the linearly polarized light of the illumination light beam, and the second power adjustment module comprises a polarizer. When the actual light power exceeds the preset range, the polarization direction of the polarizer is adjusted to adjust the light power of the light beam passing through the second power adjustment module. In specific implementation, when the actual light power exceeds the preset range, the required polarization direction of the polarizer can be determined according to the required light power of the second light beam; and the polarization direction of the polarizer is adjusted according to the required polarization direction, so as to increase the light power of the light beam passing through the second power adjustment module. This way can realize accurate control of the light power. The angle between the polarization direction of the incident linearly polarized light and the polarization direction of the polarizer is different, and the transmission rate of the linearly polarized light is different. Therefore, the angle between the polarization direction of the incident linearly polarized light and the polarization direction of the polarizer can be determined according to the actual light power and the required light power, and then the required polarization direction of the polarizer can be determined, so as to realize power adjustment.

[0093] In the case that the required light power remains constant, the required polarization direction has a correspondence with the actual light power. After the actual light power attenuates, the required polarization direction can be determined according to the correspondence, and then the polarizer is adjusted to compensate the light power to the required light power. That is, in actual work, the polarization direction of the polarizer is usually not parallel to the polarization direction of the illumination light beam to reserve a compensation range and realize subsequent compensation. In the device debugging stage, the correspondence between different required polarization directions and different actual light powers can be saved in the device for calling.

[0094] When the second detection signal includes the second interference image, if the contrast (SNR) of the second interference image is in a preset contrast range, it indicates that the second interference image can accurately reflect the characteristics of the interference fringes, and then it can be considered that the intensity of the second detection signal meets the preset condition, and the adjustment of the light power of the light beam passing through the second light power adjustment module can be stopped. The contrast of the second interference image can be the contrast in a fixed region of the second interference image, and the contrast in the fixed region will represent the overall contrast of the second interference image.

[0095] The embodiment of the present application provides a control method of a detection system. When the actual light power is out of the preset range, the light power of the light beam passing through the first power adjustment module is adjusted to adjust the intensity of the first detection signal. If the intensity of the first detection signal meets the preset condition, the adjustment of the light power of the light beam passing through the first power adjustment module is stopped. In this way, the adjustment of the light power can be based on the actual light power, and the intensity of the first detection signal is used as a verification item of the adjustment of the light power, so that the adjustment of the light power can make the intensity of the first detection signal meet the preset condition, and accurate adjustment of the light power is realized.

[0096] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instructions hardware, the foregoing program can be stored in a computer readable storage medium, and the program executes the steps of the above-mentioned method embodiments when executed; and the foregoing storage medium can be at least one of the following media: read-only memory (English: Read-only Memory, abbreviation: ROM), RAM, magnetic disc or optical disc and various media that can store program codes.

[0097] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment mainly describes the difference from other embodiments. Especially, the method embodiment is described relatively simply because it is basically similar to the system embodiment, and the relevant parts can be referred to the part of the system embodiment.

[0098] The above description is only the preferred embodiment of the present application, although the present application has been disclosed as above with the preferred embodiment, however, not to limit the present application. Any skilled person in the art, without departing from the scope of the technical scheme of the present application, can utilize the above disclosed methods and technical contents to make many possible changes and modifications to the technical scheme of the present application, or modify as equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical scheme of the present application, still belongs to the scope of protection of the technical scheme of the present application.

Claims

1. A detection system, characterized in that, The system comprises: a lighting module for providing a lighting beam; a first detection device for detecting a first to-be-detected surface to obtain a first detection signal; a light splitting module and a first power adjustment module between the lighting module and the first detection device, the light splitting module is used for periodically switching a working mode, when the working mode is a light transmission mode, the lighting beam transmits through the light splitting module and the first power adjustment module into the first detection device, when the working mode is a reflection mode, the lighting beam is reflected by the light splitting module and enters a light power detection module, the light power detection module is used for detecting the light power of the entering light beam to obtain an actual light power, and the first power adjustment module is used for adjusting the light power of the light beam transmitting through the first power adjustment module when the actual light power exceeds a preset range; the light splitting module comprises a semi-transparent and semi-reflective module, the semi-transparent and semi-reflective module comprises a light transmission path and a reflection surface, the light transmission path comprises a first surface and a second surface, the material between the first surface and the second surface is transparent material, and the light transmission path and the reflection surface periodically switch to the propagation path of the lighting beam, so that the semi-transparent and semi-reflective module periodically switches the working mode; when the light transmission path switches to the propagation path of the lighting beam, the working mode is the light transmission mode; when the reflection surface switches to the propagation path of the lighting beam, the working mode is the reflection mode; and the semi-transparent and semi-reflective module rotates at a preset speed to periodically switch the light transmission path and the reflection surface to the propagation path of the lighting beam.

2. The system of claim 1, wherein, the rotation axis of the semi-transparent and semi-reflective module is parallel to and does not coincide with the propagation path of the lighting beam, the semi-transparent and semi-reflective module comprises a first part and a second part in a plane perpendicular to the rotation axis, the first part has a light transmission path, the second part has a reflection surface on the side surface facing the lighting module, and the included angle between the reflection surface and the rotation axis is less than 90°; when the semi-transparent and semi-reflective module rotates around the rotation axis, the first part and the second part alternately switch to the propagation path of the lighting beam.

3. The system of claim 1, wherein, the rotation axis of the semi-transparent and semi-reflective module is perpendicular to the propagation direction of the lighting beam, the semi-transparent and semi-reflective module has the first surface, the second surface, a third surface and a fourth surface which are parallel to the rotation axis; the first surface and the second surface are opposite surfaces; the third surface and the fourth surface are opposite surfaces and are reflection surfaces.

4. The system of claim 3, wherein, the first surface and the second surface are arranged in parallel, the included angle between the third surface and the first surface is equal to the included angle between the third surface and the second surface, and the third surface and the fourth surface are not parallel.

5. The system of claim 1, wherein, the rotation speed of the semi-transparent and semi-reflective module is such that at least one light transmission mode and one reflection mode correspond to a single sampling of the first detection device.

6. The system according to any one of claims 1-5, characterized in that, The system further comprises: a second detection device for detecting a second to-be-detected surface to obtain a second detection signal; A total beamsplitter for splitting the illumination beam into a first beam and a second beam, the first beam entering the first detection device and the second beam entering the second detection device.

7. The system of claim 6, wherein, The first detection device comprises a first reference mirror, a first beam expander, a first beamsplitter and a first detector, the first beam is reflected by the first beamsplitter and then transmitted through the first beam expander to the first reference mirror, the part of the first beam transmitted through the first reference mirror is reflected by a first test surface on the side of the first reference mirror away from the first beam expander to form a first reflected beam, the first reflected beam passes through the first reference mirror, the first beam expander and the first beamsplitter to reach the first detector, the part of the first beam reflected by the first reference mirror forms a second reflected beam, the second reflected beam passes through the first beam expander and the first beamsplitter to reach the first detector, the first detector is configured to obtain interference information of the first reflected beam and the second reflected beam as the first detection signal; and / or, The second detection device comprises a second reference mirror, a second beam expander, a second beamsplitter and a second detector, the second beam is reflected by the second beamsplitter and then transmitted through the second beam expander to the second reference mirror, the part of the second beam transmitted through the second reference mirror is reflected by a second test surface on the side of the second reference mirror away from the second beam expander to form a third reflected beam, the third reflected beam passes through the second reference mirror, the second beam expander and the second beamsplitter to reach the second detector, the part of the second beam reflected by the second reference mirror forms a fourth reflected beam, the fourth reflected beam passes through the second beam expander and the second beamsplitter to reach the second detector, the second detector is configured to obtain interference information of the third reflected beam and the fourth reflected beam as the second detection signal.

8. The system of claim 6, wherein, The system further comprises: A second power adjustment module between the total beamsplitter and the second detection device, the second power adjustment module is configured to adjust the optical power of the light beam transmitted through the second power adjustment module when the actual optical power exceeds a preset range.

9. The system of claim 8, wherein, The illumination beam is linearly polarized light, the first power adjustment module and the second power adjustment module comprise a polarizer, the polarization direction of the polarizer is adjusted to adjust the optical power of the light beam transmitted through the polarizer.

10. The system of claim 7, wherein, The first test surface and the second test surface are surfaces on different sides of the same test object, the first detection device further comprises a first quarter-wave plate between the first beam expander and the first beamsplitter, the second detection device further comprises a second quarter-wave plate between the second beam expander and the second beamsplitter, the fast axis directions of the first quarter-wave plate and the second quarter-wave plate are orthogonal, and the first beamsplitter and the second beamsplitter are polarization beamsplitters.

11. The system of claim 6, wherein, The system further comprises: A total collimator between the illumination module and the total beamsplitter; a first converging lens and a first optical fiber between the total spectroscope and the first detecting device; a second converging lens and a second optical fiber between the total spectroscope and the second detecting device.

12. The system of any one of claims 1-5, wherein, The system further comprises: a reflecting mirror between the light splitting module and the optical power detecting module, for reflecting the light beam reflected by the light splitting module to the optical power detecting module.

13. A method of optical power adjustment, the method comprising: The method is applied to the detecting system of any one of claims 1-12, and the method comprises: adjusting the optical power of the light beam passing through the first power adjusting module when the actual optical power is out of the preset range.

14. The method of claim 13, wherein, The adjusting the optical power of the light beam passing through the first power adjusting module when the actual optical power is out of the preset range comprises: increasing the optical power of the light beam passing through the first power adjusting module when the actual optical power is less than the lower limit of the preset range.

15. The method of claim 13, wherein, The illumination light beam is linearly polarized light, and the first power adjusting module comprises a polarizer. The adjusting the optical power of the light beam passing through the first power adjusting module when the actual optical power is out of the preset range comprises: adjusting the polarization direction of the polarizer to adjust the optical power of the light beam passing through the first power adjusting module when the actual optical power is out of the preset range.

Images