Anti-vibration light path structure and reconstruction device

Abstract

The invention discloses an anti-vibration light path structure and a reconstruction device, the anti-vibration light path structure comprises a generation module, a light splitting module, an interference objective lens and a data processing module, and the generation module is configured to emit a target light beam comprising a measurement light beam and a compensation light beam; the interference objective lens is configured to scan a target point, the target light beam reaches the interference objective lens through the light splitting module and forms a target reflection light beam matched with the target point on the interference objective lens, and the target reflection light beam comprises a measurement reflection light beam matched with the measurement light beam and a compensation reflection light beam matched with the compensation light beam; the data processing module is configured to obtain the initial height of the target point based on the measurement reflection light beam and calculate vibration information brought by environment vibration based on the compensation reflection light beam so as to compensate the initial height. According to the invention, the anti-vibration light path structure and the reconstruction device can compensate the measurement height of the target point to improve the measurement precision of the target point.

Description

[0001] This application is a divisional application of the patent application with the application date of April 29, 2022, the application number of 2022104688138, and the invention title of Compensation Optical Path Structure for Improving Measurement Accuracy. Technical Field

[0002] The present disclosure relates to the field of intelligent manufacturing equipment, and particularly to an anti-vibration optical path structure and a reconstruction device. Background Art

[0003] With the increasing development of ultra-precision machining technology, ultra-precision detection technology has become increasingly important. The optical measurement method is widely used in the field of optical measurement due to its advantages of low cost and high precision. Among them, the optical measurement system based on the interference principle has the advantages of high precision and high resolution, and is commonly used for the precise measurement of physical quantities.

[0004] A white light interferometer is an ultra-precision measurement device based on white light interference measurement technology. In the prior art, a white light interferometer usually uses a single white light source to measure the object height of a to-be-measured object. During the measurement scanning process, when the optical path difference between the measurement light and the reference light is less than the coherence length of the white light source, the two beams of light can interfere to generate a white light interference signal. When the optical path difference between the measurement light and the reference light is zero, the intensity of the interference signal reaches the maximum. Therefore, the height information of the to-be-measured object can be obtained through the zero optical path difference position.

[0005] However, the measurement accuracy and accuracy of the white light interferometer are significantly affected by the environment. Generally speaking, environmental impacts include two aspects: industrial environmental impacts and natural environmental impacts. Among them, industrial environmental impacts refer to the vibration caused by people and the surrounding environment, which makes the ground generate low-frequency vibrations and then transmits them to the interferometer; natural environmental impacts refer to the vibrations generated by the interferometer due to changes in the natural environment, such as air flow, temperature changes, etc. The above two types of vibrations caused by environmental impacts are all environmental vibrations. When there is environmental vibration, the white light interference fringes generated based on the white light interferometer are prone to jitter. For example, the interference fringe images may overlap, deform, be trimmed, blurred, or have burrs, etc., resulting in large errors in the measurement results; even more seriously, if the amplitude of the interference fringe fluctuations is very large, the interference fringes cannot be observed and the measurement cannot be performed. Summary of the Invention

[0006] The present disclosure is proposed in view of the above-mentioned prior art situation, and its purpose is to provide a compensation optical path structure that can compensate the measured height of a target point to improve the measurement accuracy of the target point.

[0007] The present disclosure provides a compensation optical path structure for improving measurement accuracy, which is a compensation optical path structure for improving the measurement accuracy when a reconstruction device measures the height of a target point. The reconstruction device includes a measurement optical path structure for obtaining the initial height of the target point and the compensation optical path structure. The compensation optical path structure includes a first generation module, a beam splitting module, an interference objective lens, and a data processing module. The first generation module is configured to generate a compensation beam with a bandwidth not greater than a first preset value. The beam splitting module includes a first beam splitting unit and a second beam splitting unit. The first beam splitting unit is configured to receive the compensation beam and reflect the compensation beam to the interference objective lens. The compensation beam forms a compensation reflected beam in the interference objective lens. The data processing module compensates the initial height based on the compensation reflected beam to obtain a comprehensive measurement height.

[0008] In this case, vibration information generated by the target point due to environmental vibration can be obtained, and the above vibration information can be calculated in a visualized form. Furthermore, the initial height of the target point can be compensated based on the above vibration information to obtain a comprehensive measurement height. Moreover, the reconstruction device involved in this embodiment can perform three-dimensional shape reconstruction on the object to be measured based on the comprehensive measurement height of the target point. Thus, the reconstruction accuracy of the reconstruction device for the object to be measured can be improved.

[0009] In addition, in the compensation optical path structure involved in the present disclosure, optionally, it further includes a first receiving module signal-connected to the data processing module. The first receiving module is configured to receive the compensation reflected beam reflected by the second beam splitting unit and form a compensation interference signal. Thus, the compensation optical path structure can compensate the initial height of the target point based on the compensation interference signal. In this case, the data processing module can perform signal processing based on the compensation reflected beam to calculate the compensation information generated by the target point due to environmental vibration and compensate the initial height. Thus, the measurement accuracy of the height of the target point by the reconstruction device can be improved.

[0010] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the first receiving module includes a first receiving unit and a first lens unit. The first lens unit is disposed between the first receiving unit and the second beam splitting unit. In this case, the first lens unit can focus the compensation reflected beam on the first receiving unit, and the first receiving unit can convert the received compensation reflected beam into a compensation interference signal.

[0011] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the data processing module is configured to obtain compensation information based on the compensation interference signal, and compensate the initial height based on the compensation information to obtain the comprehensive measurement height. In this case, the data processing module can perform signal processing based on the compensated reflected light beam to calculate the compensation information generated by the environmental vibration of the target point, and compensate the initial height. Thereby, the measurement accuracy of the height of the target point by the reconstruction device can be improved.

[0012] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the interference objective lens includes a third beam splitting unit and a reference unit. The third beam splitting unit is configured to receive the compensation light beam and split the compensation light beam into a first compensation light beam reflected to the reference unit and a second compensation light beam transmitted to the target point. The first compensated target light beam is reflected by the third beam splitting unit to the reference unit and reflected by the reference unit to form a first compensated reflected light beam. The second compensated target light beam is transmitted through the third beam splitting unit to the target point and reflected by the target point to form a second compensated reflected light beam. The first compensated reflected light beam and the second compensated reflected light beam form a compensated reflected light beam. In this case, after the compensation light beam reaches the interference objective lens, it can be split into a first compensation light beam and a second compensation light beam. Among them, the first compensation light beam can be reflected to the reference unit by the third reflection unit, and the second compensation light beam can be transmitted through the third reflection unit to the target point. Since the first compensation light beam and the second compensation light beam reach different places, thereby, the first compensated reflected light beam and the second compensated reflected light beam formed by the reflection of the first compensation light beam and the second compensation light beam can have an optical path difference.

[0013] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the measurement optical path structure includes a second generation module, the beam splitting module, the interference objective lens, the data processing module, and a second receiving module. The second generation module is used to generate a measurement light beam with a bandwidth not less than a second preset value. The first preset value is not greater than the second preset value. The first beam splitting unit is further configured to receive the measurement light beam and reflect the measurement light beam to the interference objective lens. The measurement light beam forms a measurement reflected light beam in the interference objective lens. The second receiving module is configured to receive the measurement reflected light beam transmitted through the second beam splitting unit. The data processing module obtains the initial height of the target point based on the measurement reflected light beam. In this case, in the measurement optical path structure, the first measurement reflected light beam and the second measurement reflected light beam can interfere to form a measurement interference signal, and the data processing unit can obtain the initial height of the target point based on the generated measurement interference signal.

[0014] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the reconstruction device further includes a coupling unit configured to receive a compensation light beam and a measurement light beam and couple the compensation light beam and the measurement light beam. In this case, the compensation light beam and the measurement light beam can be coupled by the coupling unit into a single light beam and sent to the first beam splitting unit, and further, the compensation light beam and the measurement light beam can reach the interference objective lens synchronously, and the compensation reflected light beam and the measurement reflected light beam are formed synchronously, which is beneficial to obtaining more accurate compensation information matching the initial height of the target point.

[0015] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the measurement device further includes a timing synchronization unit configured to send control signals to the first receiving module and the second receiving module to enable the first receiving module and the second receiving module to synchronously receive the compensation reflected light beam and the measurement reflected light beam.

[0016] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the response time of the first receiving module to a light signal is not greater than the response time of the second receiving module to a light signal. In this case, the first receiving module and the second receiving module can synchronously receive light signals, and thus, the compensation information monitored by the compensation optical path structure can be synchronized with the measurement information of the measurement optical path structure, further improving the comprehensive measurement accuracy of the reconstruction device.

[0017] In addition, in the compensation optical path structure involved in the present disclosure, optionally, the reconstruction device further includes a driving module configured to adjust the relative position between the interference objective lens and the target point. In this case, the relative position between the interference objective lens and the target point can be changed, so that the initial height of the target point can be obtained based on the measurement reflected light beam, and the target point can be compensated based on the compensation reflected light beam to obtain the comprehensive measurement height.

[0018] According to the present disclosure, a compensation optical path structure capable of compensating the measured height of a target point to improve the measurement accuracy of the target point can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure will now be further explained in detail only by way of examples with reference to the accompanying drawings.

[0020] Figure 1 is a schematic diagram of an application scenario of the reconstruction device involved in the present disclosure.

[0021] Figure 2 is a block diagram of the compensation optical path structure involved in the present disclosure.

[0022] Figure 3 is a schematic diagram of the compensation optical path structure involved in the present disclosure.

[0023] Figure 4 It is a schematic diagram showing the internal optical path structure of the interference objective lens related to the present disclosure.

[0024] Figure 5 It is a schematic diagram showing the compensated interference signal and the scanning stroke related to the present disclosure.

[0025] Figure 6 It is a structural block diagram showing the measurement optical path structure related to the present disclosure.

[0026] Figure 7 It is a schematic diagram showing the measurement optical path structure related to the present disclosure.

[0027] Figure 8 It is a schematic diagram showing the measurement interference signal and the scanning stroke related to the present disclosure.

[0028] Figure 9 It is a schematic diagram showing the overall optical path structure related to the present disclosure.

[0029] Figure 10 It is a schematic diagram showing that the measurement optical path structure and the compensation optical path structure related to the present disclosure synchronously receive optical signals. Detailed implementation manners

[0030] Hereinafter, with reference to the accompanying drawings, the preferred implementation manners of the present disclosure will be described in detail. In the following description, the same reference numerals are given to the same components, and repeated descriptions are omitted. In addition, the drawings are only schematic diagrams, and the proportional relationship of the sizes between components or the shapes of components, etc. may be different from the actual ones.

[0031] It should be noted that the terms "include" and "have" in the present disclosure and any variations thereof, for example, the processes, methods, devices, products or equipment including or having a series of steps or units do not necessarily have to be limited to those steps or units clearly listed, but may include or have other steps or units not clearly listed or inherent to these processes, methods, products or equipment.

[0032] In addition, the subheadings and the like involved in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, and they only serve as a reading hint. Such subheadings should neither be understood as being used to divide the content of the article, nor should the content under the subheadings be limited only to the scope of the subheadings.

[0033] The present disclosure relates to a compensation optical path structure for improving measurement accuracy, which may sometimes be simply referred to as a compensation optical path structure hereinafter. In some examples, the compensation optical path structure for improving measurement accuracy related to the present disclosure may also be referred to as a compensation optical path structure for obtaining vibration information, or an optical path structure for obtaining compensation information.

[0034] According to the compensation optical path structure involved in the present disclosure, vibration information (which can also be referred to as compensation information) generated by environmental vibration of the target point can be obtained, and the above compensation information can be calculated in a visual form. Furthermore, the initial height of the target point can be compensated based on the above compensation information to obtain the comprehensive measurement height. Moreover, the reconstruction device involved in this embodiment can perform three-dimensional shape reconstruction on the object to be measured based on the comprehensive measurement height of the target point. Thus, the reconstruction accuracy of the reconstruction device for the object to be measured can be improved.

[0035] Hereinafter, with reference to the drawings, the compensation optical path structure involved in this embodiment will be described in detail.

[0036] Figure 1 FIG. is a schematic diagram of an application scenario of the reconstruction device 10 involved in the present disclosure. Figure 2 FIG. is a block diagram of the compensation optical path structure 100 involved in the present disclosure. Figure 3 FIG. is a schematic diagram of the compensation optical path structure 100 involved in the present disclosure.

[0037] See Figure 1 , the compensation optical path structure 100 involved in the present disclosure can be applied to the reconstruction device 10 as shown in Figure 1 . In some examples, the reconstruction device 10 can be used to measure the surface height of the object to be measured 20. In some examples, the reconstruction device 10 can be a device for measuring the surface height of the object to be measured 20 and performing three-dimensional shape reconstruction on the object to be measured 20 based on the surface height (see Figure 3 ).

[0038] In some examples, the object to be measured 20 (described later) can be referred to as a sample. The sample can be a semiconductor, a 3C electronic glass screen, a micro-nano material, an automotive component, or a super-precision device such as a MEMS device. In some examples, the sample can be a device applied in fields such as aerospace or military industry.

[0039] In some examples, the measurement points when the reconstruction device 10 measures the object under test 20 can be referred to as target points 21. That is to say, the reconstruction device 10 can be used to measure the height of the target point 21. The target point 21 can be a point, a line, or a region. In some examples, the object under test 20 can include at least one target point 21. Measuring one target point 21 can obtain the height of one target point 21, and measuring multiple target points 21 can obtain the heights of multiple target points 21. In this case, if only the height of one target point 21 needs to be obtained, the reconstruction device 10 only needs to measure one target point 21; when the reconstruction device 10 measures multiple target points 21 of the object under test 20, the three-dimensional surface topography of the object under test 20 can be reconstructed based on the heights of the multiple target points 21. In some examples, the above height can be the surface height of the object under test 20.

[0040] In some examples, the compensation optical path structure 100 can be used to improve the measurement accuracy when the reconstruction device 10 measures the height of the target point 21. Thus, the height data of the target point 21 can be more accurate.

[0041] In some examples, the reconstruction device 10 can include a compensation optical path structure 100. In some examples, the reconstruction device 10 can include a measurement optical path structure 200 (described later). The measurement optical path structure 200 can be used to obtain the initial height of the target point 21. In the measurement optical path, the initial height of the target point 21 can be obtained based on the measurement interference signal generated by the measurement beam L20.

[0042] In some examples, the reconstruction device 10 can include a compensation optical path structure 100. The compensation optical path structure 100 can be used to obtain the compensation information generated by environmental vibration of the target point 21. In some examples, the reconstruction device 10 can compensate the initial height with the above compensation information to obtain the comprehensive measurement height of the target point 21. Thus, the measurement accuracy of the reconstruction device 10 for the target point 21 can be improved. In some examples, the reconstruction device 10 can reconstruct the object under test 20 based on the comprehensive measurement accuracy of multiple target points 21 to obtain a more accurate three-dimensional surface topography.

[0043] In some examples, the measurement beam L20 can be white light. In some examples, the wavelength of the measurement beam L20 can be 400nm - 700nm, for example, it can be 400nm, 450nm, 500nm, 550nm, 6000nm, 650nm or 700nm. In this case, when the reconstruction device 10 measures the information of the object under test 20, clearer image information of the surface of the object under test 20 can be obtained.

[0044] In some examples, the compensation optical path structure 100 may compensate for the initial height based on the compensation interference signal generated by the compensation light beam L10. In some examples, the compensation light beam L10 may be infrared light. The wavelength of the compensation light beam L10 may be not less than 900 nm. For example, the wavelength of the compensation light beam L10 may be 950 nm, 980 nm, 1000 nm, etc. In this case, the bands spanned by the measurement light beam L20 and the compensation light beam L10 have a sufficiently long interval such that the measurement light beam L20 and the compensation light beam L10 can have a higher isolation degree, thereby being able to reduce the influence of the compensation light beam L10 on the measurement light beam L20 during the measurement process.

[0045] In some examples, the bandwidth of the compensation light beam L10 may be not greater than a first preset value. The bandwidth of the measurement light beam L20 may be not less than a second preset value, and the first preset value may be not greater than the second preset value. For example, the first preset value may be 50 nm, and the second preset value may be 100 nm.

[0046] See Figure 2 and Figure 3 In this embodiment, the compensation optical path structure 100 may include a first generation module 110, a beam splitting module 120, an interference objective lens 130, and a data processing module 140.

[0047] Among them, the first generation module 110 may be used to generate the compensation light beam L10. The beam splitting module 120 may be used to change the propagation direction of the compensation light beam L10. The interference objective lens 130 may be used to form a compensation reflected light beam L10'. The data processing module 140 may compensate for the initial height based on the compensation reflected light beam L10' to obtain a comprehensive measurement height.

[0048] As described above, the first generation module 110 may be used to generate the compensation light beam L10. In some examples, the compensation light beam L10 may be narrowband light with a bandwidth not greater than the first preset value. Therefore, the first generation module 110 may be a narrowband light source. In some examples, the propagation direction of the compensation light beam L10 generated by the first generation module 110 may be changed by the beam splitting module 120.

[0049] In some examples, the beam splitting module 120 may include a first beam splitting unit 121. The first beam splitting unit 121 may be used to receive the compensation light beam L10. The first beam splitting unit 121 may be used to reflect the compensation light beam L10. In some examples, the first beam splitting unit 121 may be used to receive the compensation light beam L10 and reflect the compensation light beam L10. Thus, the propagation direction of the compensation light beam L10 can be changed based on the setting of the first beam splitting unit 121.

[0050] In some examples, the compensation optical path structure 100 may further include a beam adjustment module 160. The beam adjustment module 160 can be used to adjust the convergence of the compensation beam L10. In some examples, the beam adjustment module 160 can be disposed between the first generation module 110 and the first beam splitting unit 121 to adjust the convergence of the compensation beam L10.

[0051] In some examples, the beam adjustment module 160 may include a converging unit 161 and a collimating unit 162. The converging unit 161 can be used to converge the compensation beam L10 into a beam. The collimating unit 162 can be used to convert the compensation beam L10 from divergent light into collimated light. In this case, after passing through the first lens unit 152, the compensation beam L10 can be converged into a beam and then sent to the collimating unit 162, and the collimating unit 162 converts the converged compensation beam L10 into collimated light and sends it to the first beam splitting unit 121. Thus, the divergence of the compensation beam L10 can be reduced and the energy loss of the compensation beam L10 can be reduced.

[0052] In some examples, the compensation optical path structure 100 may also not include the beam adjustment module 160.

[0053] In some examples, the compensation beam L10 reflected by the first beam splitting unit 121 can be sent to the interference objective lens 130. The compensation beam L10 can form a compensation reflected beam L10' in the interference objective lens 130.

[0054] In some examples, the beam splitting module 120 may further include a second beam splitting unit 122. The second beam splitting unit 122 can be used to change the propagation direction of the compensation reflected beam L10'.

[0055] Figure 4 is a schematic diagram showing the internal optical path structure of the interference objective lens 130 involved in the present disclosure.

[0056] See Figure 4 , in some examples, the interference objective lens 130 may include a third beam splitting unit 131 and a reference unit 132. Among them, the third beam splitting unit 131 can be configured to receive the compensation beam L10 and split the compensation beam L10 into a first compensation beam L11 and a second compensation beam L12. In some examples, the third beam splitting unit 131 can also be configured to reflect the first compensation beam L11 to the reference unit 132 and transmit the second compensation beam L12 to the target point 21.

[0057] In some examples, the first compensation target beam L30 can be reflected by the third beam splitting unit 131 to the reference unit 132 and then reflected by the reference unit 132 to form the first compensation reflected beam L10'. In some examples, the second compensation beam L12 can be transmitted by the third beam splitting unit 131 to the target point 21 and then reflected by the target point 21 to form the second compensation reflected beam L10'. In some examples, the first compensation reflected beam L10' and the second compensation reflected beam L10' can form the compensation reflected beam L10'. Specifically, the third beam splitting unit 131 can also be configured to synthesize the first compensation beam L11 and the second compensation beam L12 to form the compensation reflected beam L10'. In other words, the compensation reflected beam L10' can include the first compensation reflected beam L10' and the second compensation reflected beam L10'. In this case, after the compensation beam L10 reaches the interference objective lens 130, it can be decomposed into the first compensation beam L11 and the second compensation beam L12. Among them, the first compensation beam L11 can be reflected by the third beam splitting unit 131 to the reference unit 132, and the second compensation beam L12 can be transmitted through the third beam splitting unit to the target point 21. Since the first compensation beam L11 and the second compensation beam L12 reach different places, thus, the first compensation reflected beam L10' and the second compensation reflected beam L10' formed by the reflection of the first compensation beam L11 and the second compensation beam L12 can have an optical path difference.

[0058] Figure 5 FIG. is a schematic diagram showing the compensation interference signal and the scanning stroke involved in the present disclosure.

[0059] Wherein, I can be the light intensity, and z can be the scanning stroke.

[0060] As described above, the third beam splitting unit 131 can be configured to synthesize the first compensation beam L11 and the second compensation beam L12 to form the compensation reflected beam L10'. In some examples, the first compensation beam L11 and the second compensation beam L12 included in the compensation reflected beam L10' can have an optical path difference. Thus, the first compensation beam L11 and the second compensation beam L12 can interfere to generate a compensation interference signal.

[0061] In some examples, the direction of the relative displacement between the interference objective lens 130 and the object under test 20 can be referred to as the scanning direction. Refer to Figure 3 , the scanning direction can be as shown in the Figure 3 Z direction of. In some examples, the relative displacement change between the interference objective lens 130 and the object under test 20 when the reconstruction device 10 measures a target point 21 can be referred to as the scanning stroke.

[0062] In some examples, the scanning stroke may be not less than the coherence length of the measurement beam L20. In some examples, a compensation beam L10 whose bandwidth is not greater than a first preset value may be referred to as a narrowband beam. The narrowband beam has a relatively long coherence length. Thus, over the entire scanning stroke for measuring a target point 21, both the first compensation reflected beam L10' and the second compensation reflected beam L10' included in the compensation reflected beam L10' can interfere to generate a compensation interference signal. Refer to Figure 5 , in some examples, the compensation interference signal may be a sine wave signal, and the compensation interference signal can be formed over the entire scanning stroke.

[0063] In some examples, the vibration of the target point 21 may be monitored based on the compensation beam L10. In other words, compensation information (vibration information) generated by the environmental vibration during the measurement of the target point 21 can be obtained based on the compensation beam L10. Thus, the initial height can be compensated based on the compensation beam L10. In some examples, the compensation information of the target point 21 during the measurement can be obtained based on the compensation interference signal. The compensation interference signal may be a sine wave signal. In some examples, the compensation interference signal of the compensation optical path may be referred to as a vibration monitoring signal.

[0064] As described above, the beam splitting module 120 may further include a second beam splitting unit 122. The second beam splitting unit 122 may be arranged in the same direction as the first beam splitting unit 121. The second beam splitting unit 122 may be a dichroic beam splitter. In some examples, after the compensation reflected beam L10' exits the interference objective lens 130, it may reach the second beam splitting unit 122 via the first beam splitting unit 121. In other words, the second beam splitting unit 122 may be configured to receive the compensation reflected beam L10' transmitted through the first beam splitting unit 121. In some examples, the second receiving unit 221 may reflect the compensation reflected beam L10' to the first receiving module 150.

[0065] In some examples, the first receiving module 150 may be configured to receive the compensation reflected beam L10' reflected by the second beam splitting unit 122 and form a compensation interference signal. Thus, the compensation optical path structure 100 can compensate the initial height of the target point 21 based on the compensation interference signal.

[0066] In some examples, the first receiving module 150 may include a first receiving unit 151 and a first lens unit 152. Among them, the first lens unit 152 may be disposed between the first receiving unit 151 and the second beam splitting unit 122. In some examples, the first receiving unit 151 may be a photodetector. Preferably, the first receiving unit 151 may be a point photodetector. Thus, the first receiving unit 151 can convert the received compensated reflected beam L10' into a compensated interference signal. In some examples, the point photodetector may have the advantages of high speed and large dynamic range for receiving signals. In this case, using the point photodetector as the first receiving unit 151 enables the reconstruction device 10 to quickly and accurately receive the light intensity change information of the target point 21 during the measurement of the target point 21. Thus, more accurate compensation information can be obtained. In some examples, the first lens unit 152 may be a converging lens with the function of converging light beams. In this case, the first lens unit 152 can focus the compensated reflected beam L10' on the first receiving unit 151. In some examples, the first receiving module 150 may not include the first lens unit 152.

[0067] In some examples, a plurality of first receiving units 151 may be included. In some examples, the number of the first receiving units 151 may be not less than 3. For example, it may include 3, 4, 5, etc. first receiving units 151. In some examples, when the reconstruction device 10 includes a plurality of first receiving units 151, the plurality of first receiving units 151 can monitor the vibration information of a plurality of target points 21, and then a vibration surface can be synthesized based on the plurality of vibration information. In this case, the reconstruction device 10 can not only achieve the function of compensating the initial height of the target point 21, but also achieve the function of compensating the angular change of the target point 21.

[0068] In some examples, the first receiving module 150 may be signal-connected to the data processing module 140. The data processing module 140 may compensate the initial height based on the compensated reflected beam L10' to obtain the comprehensive measurement height. In this case, the data processing module 140 may perform signal processing based on the compensated reflected beam L10' to calculate the compensation information generated by the environmental vibration of the target point 21 and compensate the initial height. Thus, the measurement accuracy of the height of the target point 21 by the reconstruction device 10 can be improved.

[0069] Specifically, the data processing module 140 can be signal-connected to the first receiving module 150. More specifically, it is signal-connected to the first receiving unit 151. Thus, the first receiving module 150 can send the compensated interference signal to the data processing module 140. The data processing module 140 can be configured to obtain compensation information based on the compensated interference signal, and compensate the initial height based on the compensation information to obtain the comprehensive measurement height. In this case, the data processing module 140 can obtain the compensation information generated by the environmental vibration of the target point 21 based on the compensated interference information, and reduce the measurement error generated by the environmental vibration after compensating the initial height based on the compensation information, thereby improving the measurement accuracy of the reconstruction device 10.

[0070] In some examples, a data acquisition unit 170 can be provided between the data processing module 140 and the first receiving unit 151. The compensated interference signal can be sent to the data processing module 140 via the data acquisition unit 170.

[0071] In some examples, the compensation information can refer to the measurement error generated by the environmental vibration, that is, the vibration information mentioned above.

[0072] In summary, according to the compensation optical path structure 100 involved in the present disclosure, the measurement error generated by the environmental vibration during the measurement of the height of the target point 21 can be obtained. In the present disclosure, the measurement error generated by the environmental vibration can be used as compensation information or vibration information. And the compensation optical path structure 100 involved in the present disclosure can also correct (compensate) the initial height based on the compensation information to obtain the comprehensive measurement height of the target point 21, thereby improving the measurement accuracy of the reconstruction device 10.

[0073] Figure 6 FIG. shows a structural block diagram of the measurement optical path structure 200 involved in the present disclosure. Figure 7 FIG. shows a schematic diagram of the measurement optical path structure 200 involved in the present disclosure.

[0074] As described above, the reconstruction device 10 can obtain the initial height of the target point 21 based on the measurement optical path structure 200. In some examples, the measurement optical path structure 200 can include a second generating module 210, a beam splitting module 120, an interference objective lens 130, a data processing module 140, and a second receiving module 220.

[0075] Among them, the second generating module 210 can be used to generate a measurement beam L20 with a bandwidth not less than a second preset value. The first beam splitting unit 121 can also be configured to receive the measurement beam L20 and reflect the measurement beam L20 to the interference objective lens 130, and the measurement beam L20 forms a measurement reflected beam L20' on the interference objective lens 130.

[0076] Specifically, as described above, the interference objective lens 130 may include a third beam splitting unit 131 and a reference unit 132. Among them, the third beam splitting unit 131 may also be configured to receive the measurement beam L20 and split the measurement beam L20 into a first measurement beam and a second measurement beam. In some examples, the third beam splitting unit 131 may also be configured to reflect the first measurement beam to the reference unit 132 and transmit the second measurement beam to the target point 21. In some examples, the first measurement target beam may be reflected to the reference unit 132 via the third beam splitting unit 131 and reflected by the reference unit 132 to form a first measurement reflected beam. In some examples, the second measurement beam may be transmitted to the target point 21 via the third beam splitting unit 131 and reflected by the target point 21 to form a second measurement reflected beam. In some examples, the first measurement reflected beam and the second measurement reflected beam may form a measurement reflected beam L20'. Specifically, the third beam splitting unit 131 may also be configured to synthesize the first measurement beam and the second measurement beam to form the measurement reflected beam L20'. In other words, the measurement reflected beam L20' may include the first measurement reflected beam and the second measurement reflected beam. In this case, after the measurement beam L20 reaches the interference objective lens 130, it can be split into a first measurement beam and a second measurement beam. Among them, the first measurement beam may be reflected to the reference unit 132 via the third beam splitting unit 131, and the second measurement beam may be transmitted to the target point 21 via the third beam splitting unit 131. Since the first measurement beam and the second measurement beam reach different places, thus, the first measurement reflected beam and the second measurement reflected beam formed by the reflection of the first measurement beam and the second measurement beam can have an optical path difference (the specific principle can be referred to Figure 4 ).

[0077] As described above, the measurement beam L20 may be white light. The bandwidth of the measurement beam L20 may not be less than a second preset value. In some examples, the measurement beam L20 with a bandwidth not less than the second preset value is called broadband white light.

[0078] Figure 8 It is a schematic diagram showing the measurement interference signal and the scanning stroke involved in the present disclosure.

[0079] In some examples, the first measured reflected light beam and the second measured reflected light beam may form an interference. Therefore, the reconstruction device 10 may obtain the initial height of the target point 21 based on the measured interference signal of the first measured reflected light beam and the second measured reflected light beam. Since the coherence length of broadband white light is short, when the optical path difference between the first measured reflected light beam and the second measured reflected light beam is not greater than the coherence length of the measurement light beam L20, the first measured reflected light beam and the second measured reflected light beam may interfere to generate interference fringes. In some examples, when the optical path difference between the first measured reflected light beam and the second measured reflected light beam is zero, the interference fringes are the most obvious, the intensity of the measured interference signal can reach the maximum value, and the reconstruction device 10 may obtain the initial height of the target point 21 based on the measured interference signal at this time. Therefore, the initial height of the target point 21 may be obtained by locating the position of zero optical path difference.

[0080] See Figure 8 , in some examples, the measured interference signal collected by the measurement optical path structure 200 may be a sine wave signal modulated by a Gaussian envelope. Specifically, at the zero optical path difference position, an interference peak appears in the measured interference signal. The initial height of the target point 21 may be obtained based on the interference peak. When the optical path difference between the first measured reflected light beam and the second measured reflected light beam is greater than the coherence length of the measurement light beam L20, the first measured reflected light beam and the second measured reflected light beam do not interfere and thus there is no measured interference signal.

[0081] In some examples, when the optical path difference between the first measured reflected light beam and the second sub-measured reflected light beam L20′ is zero, the vertical distance between the reference unit 132 and the third beam splitting unit 131 may be equal to the vertical distance between the third beam splitting unit 131 and the target point 21.

[0082] As described above, the scanning stroke may not be less than the coherence length of the measurement light beam L20. In this case, the measured interference signal generated by the interference of the measured reflected light beam L20′ during the scanning stroke can be completely displayed, the peak of the measured interference signal can be accurately judged, and at the same time, the compensation information can be obtained based on the compensation interference signal of the compensation reflected light beam L10′ during the entire scanning stroke.

[0083] In some examples, the measurement optical path structure 200 may further include a second receiving module 220. The second receiving module 220 may be configured to receive the measured reflected light beam L20′ transmitted through the second beam splitting unit 122. In some examples, the second receiving module 220 may include a second receiving unit 221 and a second lens unit 222. The second lens unit 222 may be a lens unit having the same function as the first lens unit 152.

[0084] In some examples, the second receiving unit 221 can be a CDD camera or a CMOS camera. Thus, the second receiving unit 221 can convert the received measurement reflected light beam L20′ into a measurement interference signal.

[0085] In some examples, the data processing module 140 can obtain the initial height of the target point 21 based on the measurement reflected light beam L20′. Specifically, the second receiving unit 221 can be signal-connected to the data processing module 140. The data processing module 140 can obtain the initial height of the target point 21 based on the interference signal.

[0086] In some examples, the measurement optical path structure 200 can also include a beam adjustment module 160, that is, it can include a converging unit 161 and a collimating unit 162. In some examples, the measurement optical path structure 200 may not include the converging unit 161 and the collimating unit 162.

[0087] In this case, in the measurement optical path structure 200, the first measurement reflected light beam and the second measurement reflected light beam can interfere to form a measurement interference signal, and the data processing unit can obtain the initial height of the target point 21 based on the generated measurement interference signal.

[0088] Figure 9 It is a schematic diagram showing the overall optical path structure 300 involved in the present disclosure.

[0089] As described above, the reconstruction device 10 can include a measurement optical path structure 200 and a compensation optical path structure 100. Refer to Figure 9 , in some examples, the measurement optical path structure 200 and the compensation optical path structure 100 can be combined into an overall optical path structure 300. That is, the overall optical path structure 300 can include any one of the above modules or units.

[0090] In some examples, the reconstruction device 10 can also include a driving module (not shown), and the driving module can be configured to adjust the relative position between the interference objective lens 130 and the target point 21. In some examples, the driving module can adjust the interference objective lens 130 to be away from or close to the target point 21. In some other examples, the driving module can adjust the target point 21 to be away from or close to the interference objective lens 130. In this case, the relative position between the interference objective lens 130 and the target point 21 can be changed, so that the initial height of the target point 21 can be obtained based on the measurement reflected light beam L20′, and the target point 21 can be compensated based on the compensation reflected light beam L10′ to obtain the comprehensive measurement height.

[0091] In some examples, the reconstruction device 10 may further include a carrier module. The carrier module can be used to carry the object to be measured 20. That is, the above-mentioned driving module can drive the relative position between the interference objective lens 130 and the carrier module to change. In some examples, the driving module can be configured to adjust the relative distance between the carrier module and the interference objective lens 130, so that the optical path differences between a plurality of target points 21 included in the surface of the object to be measured 20 and the reference unit 132 of the interference objective lens 130 are successively zero. In this case, the reconstruction device 10 can obtain the heights of the plurality of target points 21 based on the measured interference signals of the plurality of target points 21, compensate for the heights of the plurality of target points 21 based on the measured interference signals of the plurality of target points 21, and thus can reconstruct a more accurate three-dimensional surface topography of the object to be measured 20.

[0092] In some examples, if the measurement optical path structure 200 and the compensation optical path structure 100 are combined into a total optical path structure 300. Then the reconstruction device 10 may further include a coupling unit 310, and the coupling unit 310 can be configured to receive the compensation beam L10 and the measurement beam L20 and couple the compensation beam L10 and the measurement beam L20. At this time, the coupling unit 310 can be arranged at an angle of 45° with the outgoing direction of the compensation beam L10. Or it can be said that it is arranged at an angle of 45° with the outgoing direction of the measurement beam L20 (see Figure 9 ). In this case, the compensation beam L10 and the measurement beam L20 can be coupled by the coupling unit 310 into a single beam and sent to the first beam splitting unit 121, so that the compensation beam L10 and the measurement beam L20 can reach the interference objective lens 130 synchronously, and the compensation reflected beam L10′ and the measurement reflected beam L20′ can be formed synchronously, which is beneficial to obtaining more accurate compensation information matching the initial height of the target point 21.

[0093] In some examples, the compensation beam L10 and the measurement beam L20 after being coupled by the coupling unit 310 can be used as the target beam L30. The first beam splitting unit 121 receives the target beam L30 and reflects the target beam L30 to the interference objective lens 130. Then, the target beam L30 forms a target reflected beam L30′ in the interference objective lens 130 (specifically how to form the target reflected beam L30′ can refer to Figure 4, which will not be elaborated here). Next, the target reflected light beam L30' emitted from the interference objective lens 130 can be transmitted to the second beam splitting unit 122 through the first beam splitting unit 121. The second beam splitting unit 122 can receive the target light beam L30' and decouple the target light beam L30' into a compensation reflected light beam L10' that matches the compensation light beam L10 and a measurement reflected light beam L20' that matches the measurement light beam L20. Next, the second beam splitting unit 122 reflects the compensation reflected light beam L10' to the first receiving module 150 and transmits the measurement reflected light beam L20' to the second receiving module 220. Moreover, the first receiving unit 151 and the second receiving unit 221 can synchronously receive the compensation reflected light beam L10' and the measurement reflected light beam L20'. Finally, the data processing module 140 obtains the initial height of the target point 21 based on the measurement reflected light beam L20', obtains the compensation information of the target point 21 based on the compensation reflected light beam L10' and compensates the initial height to obtain the comprehensive measurement height.

[0094] Figure 10 FIG. is a schematic diagram showing the synchronous reception of optical signals by the measurement optical path structure 200 and the compensation optical path structure 100 involved in the present disclosure.

[0095] In some examples, the reconstruction device may further include a timing synchronization unit 320, and the timing synchronization unit 320 may be configured to send a control signal to the first receiving module 150 and the second receiving module 220 so that the first receiving module 150 and the second receiving module 220 can synchronously receive the compensation reflected light beam L10' and the measurement reflected light beam L20'. In this case, the first receiving module 150 and the second receiving module 220 can synchronously receive optical signals. Thus, the compensation information monitored by the compensation optical path structure 100 can be synchronized with the measurement information of the measurement optical path structure 200, further improving the comprehensive measurement accuracy of the reconstruction device 10.

[0096] Specifically, the timing synchronization unit 320 can be signal-connected to the first receiving unit 151, and the timing synchronization unit 320 can be signal-connected to the second receiving unit 221. The timing synchronization unit 320 can send a frame synchronization pulse to the signals of the first receiving unit 151 and the second receiving unit 221. And the time interval of each frame can be the same. One data information (i.e., white light interference signal and compensation interference signal) of the target point 21 can be obtained for each frame. In some other examples, multiple data information of the target point 21 can be obtained for each frame. In some examples, data of N frames can be collected to reconstruct the three-dimensional surface topography of the object to be measured 20. N can be an even number.

[0097] In some examples, to reduce the impact of environmental vibration on the measurement accuracy, the rate at which the first receiving unit 151 and the second receiving unit 221 receive optical signals can be increased as much as possible. As described above, the first receiving unit 151 can be a point photodetector. The second receiving unit 221 can be a CDD camera or a CMOS camera. Then, the frame rate of the first receiving unit 151 can be 1 MHz - 1 GHz. The frame rate of the second receiving unit 221 can be 50 Hz - 1 kHz. Therefore, the sampling rate of the first receiving unit 151 can be much greater than that of the second receiving unit 221. That is to say, the time for the first receiving unit 151 to respond to an optical signal can be no greater than the response time of the second receiving unit 221 to respond to an optical signal. Let the time for the first receiving unit 151 to receive an optical signal be τ1, and the time for the second receiving unit 221 to receive an optical signal be τ2. Combining the above frame synchronization pulses (Frame1, Frame2, Frame3...), the time schematic diagram of the synchronous acquisition of optical signals by the measurement optical path structure 200 and the compensation optical path structure 100 can be as Figure 10 shown. In this case, the sampling integration time of the first receiving unit 151 can be much lower than that of the second receiving unit 221, so that the vibration information monitored by the compensation optical path structure 100 can more accurately reflect the environmental vibration.

[0098] In some examples, using the same timing synchronization unit 320 to control the synchronous trigger sampling of the first receiving unit 151 and the second receiving unit 221 can make the interference signals of the compensation optical path structure 100 and the measurement optical path structure 100 have synchrony, and the vibration information monitored by the compensation optical path structure 100 can be synchronized with the initial height obtained by the measurement optical path structure 200.

[0099] Next, it will be specifically described how to obtain compensation information based on the compensation optical path structure 100 and compensate the initial height to obtain the comprehensive measurement height.

[0100] In some examples, the intensity model of the compensation interference signal formed by the compensation reflected light beam L10' can be expressed as formula (1):

[0101] I(t) = A + Bcos[θ + φ(t)] (1)

[0102] where θ can be the wavefront phase, φ(t) can be the phase shift that changes with time, and A and B can be the DC term coefficient and the AC term coefficient respectively. I(t) can be the light intensity, and t is the scanning time.

[0103] If the first receiving unit 151 acquires the compensation interference signals from the k-th frame to the p-th frame, the interference light intensities of the k-th frame and the p-th frame can be formula (2) and formula (3) respectively:

[0104] Ik = A + B cos(θ) (2)

[0105]

[0106] where I k can be the light intensity compensating for the reflected beam L10' at the k-th frame, I p can be the light intensity compensating for the reflected beam L10' at the p-th frame, can be the phase increment.

[0107] In some examples, formulas (2) and (3) can be further derived to obtain the wavefront phase θ of the target point 21 of the object 20 to be measured, and the wavefront phase θ can satisfy formula (4):

[0108]

[0109] In some examples, the phase shift increment between two frames can be taken as ("four-step phase-shifting method"), then the wavefront phase θ:

[0110]

[0111] In some examples, the true phase value corresponding to the target point 21 of the first receiving unit 151 can be set as θ. Since the value range of the tangent function is [-π / 2, +π / 2] and the function period is π, according to the light intensity sequence (I1, I2, I3, ..., I N ) collected in N frames, the interference phase shift between adjacent frames can be calculated:

[0112] For frames 1 - 2: θ1 = θ + δ1

[0113] For frames 3 - 4: θ2 = Mod π (θ + π + δ2) = θ + δ2

[0114] For frames 5 - 6: θ3 = Mod π (θ + 2π + δ3) = θ + δ3

[0115] …

[0116] For frames k - 1 - k: θ k = Mod π (θ + 2π + δ k / 2 ) = θ + δ k / 2

[0117] …

[0118] For frames N - 1 - N: θ N / 2 = Mod π (θ + 2π + δ N / 2 ) = θ + δ N / 2

[0119] where k = 1, 2, ..., N / 2, δ k is the additional phase shift caused by vibration noise between the (2k - 1)-th frame and the 2k-th frame.

[0120] In some examples, the above N / 2 expressions can be added and averaged to obtain formula (6):

[0121]

[0122] When the acquisition frame rate is high enough, the averaged vibration component can approach zero:

[0123]

[0124] Therefore, the wavefront phase corresponding to the surface of the target point 21 of the object to be measured 20 by the first receiving unit 151 can be represented by formula (7):

[0125]

[0126] where N is the total number of frames acquired, and θ k represents the phase change of the target point in adjacent frames (the (2k - 1)-th to 2k-th frames), From this, an accurate wavefront phase can be obtained.

[0127] In some examples, the error caused by environmental vibration can be calculated based on the above accurate wavefront phase. In some examples, the error caused by environmental vibration can also be referred to as vibration interference.

[0128] In some examples, the additional phase shift caused by vibration noise in each frame j can be calculated based on formula (8):

[0129]

[0130] where I j is the light intensity of the compensated interference signal in the j-th frame, I j-1 is the light intensity of the compensated interference signal in the (j - 1)-th frame, A is the DC term coefficient of the intensity model of the compensated interference signal, and θ is the wavefront phase corresponding to the target point 21 by the second receiving unit 720.

[0131] In some examples, the first frame is the initial frame, and the phase change caused by vibration can be zero, i.e., δ j = 0. From this, the phase change caused by vibration in each frame of the target point 21 can be obtained based on formula (8).

[0132] In some examples, after arranging multiple (≥3) first receiving units 151, different Z - direction translation amounts can be detected simultaneously at multiple target points 21, and then a vibration plane can be fitted. In addition to characterizing the translation noise of the target points 21, it can also characterize the angular swing noise of the target points 21.

[0133] In some examples, the initial height of the target point 21 can also be compensated based on formula (8). In some examples, the vibration of each frame j can be calculated based on the monitoring signal, and the phase change caused by the vibration of the j - th frame is δ j , correspondingly, the displacement caused in the z - direction can be represented by formula (9):

[0134]

[0135] where λ monitor can be the central wavelength of the compensation beam L10.

[0136] Assume that the measured interference signal of the reflected beam L20′ is measured in the j - th frame, and the sampling data of the target point 21 at the z - position sequence z j is (z j , I j ). Considering the displacement caused by environmental vibration, the actual sampling position (the position of the object 20 to be measured) can be z j +ε j , so the sampling data can be corrected to:

[0137]

[0138] As can be seen from the above, the sampling data of the uncompensated target point 21 can be a regular position sequence (initial height) or time sequence. However, by calculating the error caused by environmental vibration and compensating the above error into the initial height, an irregular but accurate position sequence (comprehensive measurement height) or time - sequence sampling can be obtained.

[0139] In summary, the present disclosure can obtain the initial height of the target point 21 based on the measured interference signal generated by the reflected beam L20′. The initial height can be compensated based on the compensation interference signal of the compensation beam L10′ during the entire scanning stroke. The compensated initial height can be the comprehensive measurement height. In some examples, the comprehensive measurement heights of multiple target points 21 can be obtained based on the compensation optical path structure 100 of the present disclosure.

[0140] In this embodiment, the heights of multiple target points 21 of the object to be measured 20 can be obtained based on the measurement interference signals of the multiple target points 21 of the object to be measured 20 obtained from the above disclosure, and the heights of the multiple target points 21 can be compensated based on the measurement interference signals of the multiple target points 21, so that a more accurate three-dimensional surface topography of the object to be measured 20 can be reconstructed.

[0141] Although the present disclosure has been specifically described above in conjunction with the accompanying drawings and examples, it should be understood that the above description does not limit the present disclosure in any way. Those skilled in the art can make deformations and changes to the present disclosure as needed without departing from the essence and scope of the present disclosure, and these deformations and changes all fall within the scope of the present disclosure.

Claims

1. An anti-vibration optical path structure is an anti-vibration optical path structure used to obtain the initial height of a target point and compensate for the initial height, characterized in that, The anti-vibration optical path structure includes a generation module, a beam splitting module, an interference objective lens, and a data processing module. The generation module is configured to emit a target beam including a measurement beam and a compensation beam. The interference objective lens is configured to scan the target point. The target beam reaches the interference objective lens via the beam splitting module and forms a target reflected beam matching the target point in the interference objective lens. Among them, the beam splitting module is configured to be able to change the propagation direction of the beam. The target reflected beam includes a measurement reflected beam matching the measurement beam and a compensation reflected beam matching the compensation beam. The data processing module is configured to obtain the initial height of the target point based on the measurement reflected beam, and calculate vibration information caused by environmental vibration based on the compensation reflected beam to compensate the initial height.

2. The anti-vibration optical path structure according to claim 1, characterized in that The data processing module is configured to calculate the vibration information of multiple target points based on the compensation reflected beam, synthesize a vibration surface based on the multiple vibration information, and compensate for the angular change of the multiple target points based on the vibration surface.

3. The anti-vibration optical path structure according to claim 1 or 2, characterized in that The beam splitting module includes a first beam splitting unit and a second beam splitting unit. The first beam splitting unit is configured to receive the target beam and reflect the target beam to the interference objective lens. The second beam splitting unit is configured to receive the target reflected beam transmitted by the first beam splitting unit and decouple the target reflected beam into the measurement reflected beam and the compensation reflected beam.

4. The anti-vibration optical path structure according to claim 3, characterized in that, It further includes a receiving module signal-connected to the data processing module. The receiving module includes a second receiving unit and at least one first receiving unit. The first receiving unit is configured to receive the compensation reflected beam reflected by the second beam splitting unit and form a compensation interference signal. The second receiving unit is configured to receive the compensation reflected beam transmitted by the second beam splitting unit and form a measurement interference signal.

5. The anti-vibration optical path structure according to claim 4, characterized in that, The data processing module includes a timing synchronization unit. The timing synchronization unit is configured to send a control signal to the first receiving unit and the second receiving unit so that the first receiving unit and the second receiving unit synchronously receive the compensation reflected beam and the measurement reflected beam.

6. The anti-vibration optical path structure according to claim 4, wherein The data processing module calculates the vibration information of the target point based on the interference signal of the compensation reflected beam received by the first receiving unit during the entire scanning stroke.

7. The anti-vibration optical path structure according to claim 1, characterized in that, The generation module includes a first generation module and a second generation module. The first generation module is configured to generate a compensation beam with a bandwidth not greater than a first preset value. The second generation module is used to generate a measurement beam with a bandwidth not less than a second preset value. Among them, the first preset value is not greater than the second preset value.

8. The anti-vibration optical path structure according to claim 1, characterized in that Compensating the initial height includes: obtaining a compensation interference signal of the target point based on the compensation beam; Establishing an intensity model of the compensation interference signal. The intensity model characterizes the light intensity change of the compensation interference signal at least caused by vibration. Obtain a multi-frame light intensity sequence of the compensated interference signal, and take every two adjacent frames as a group. Calculate the interference phase shift of each group of adjacent frames based on the multi-frame light intensity sequence. The interference phase shift of each group of adjacent frames is expressed by the wavefront phase of the compensated interference signal at the target point and the additional phase shift amount caused by vibration. Increase the number of frames of the multi-frame light intensity sequence so that the mean value of the additional phase shift amounts of multiple groups of adjacent frames approaches zero, in order to obtain the wavefront phase characterized by the mean value of the interference phase shifts of multiple groups of adjacent frames. Obtain the additional phase shift amount caused by vibration in each frame based on the interference phase shift of every two adjacent frames and the wavefront phase, and Compensate the initial height based on the additional phase shift amount.

9. The anti-vibration optical path structure according to claim 8, characterized in that, Obtain vibration information caused by vibration based on the additional phase shift amount, and compensate the initial height based on the vibration information. The vibration information satisfies: Among them, ε j is the vibration information caused by vibration between the (j - 1)-th frame and the j-th frame, λ monitor is the central wavelength of the compensation beam, and δ j is the additional phase shift amount between the (j - 1)-th frame and the j-th frame.

10. A reconstruction device with an anti-vibration optical path structure, characterized in that, The reconstruction device includes the anti-vibration optical path structure according to any one of claims 1 to 9. The reconstruction device further includes a carrying module and a driving module. The carrying module is configured to carry the object to be measured having a target point, and the driving module is configured to adjust the relative position between the interference objective lens and the carrying module.

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