Polarization phase shift coherence gradient sensing device and method for real-time deformation field measurement

Abstract

The embodiment of the present application proposes a polarization phase shift coherent gradient sensing device and method for real-time deformation field measurement, including a laser modulation component, which emits laser to the optical surface to be measured; the reflected light beam is reflected to the polarization component through the prism component, which includes a polarizer, a transmission grating group and a filter lens arranged in sequence along the optical path direction of the reflected light beam; the transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating, the reflected light beam is diffracted on the front polarization transmission grating, and the diffracted light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form an interference light beam; the interference light beam is converged into a diffraction spot through the filter lens; the image acquisition and processing system collects the diffraction spot to perform polarization phase shift coherent gradient sensing measurement and post-processing calculation. The present application can accurately and effectively realize the real-time and accurate measurement of the deformation field of the object to be measured, and the principle is simple, and it reduces the volume of the traditional coherent gradient sensor and expands the scope of use of the coherent gradient sensor.

Description

Technical Field

[0001] The present application relates to the field of on-site real-time manufacturing technology such as semiconductor devices and directed energy deposition, and in particular to a polarization phase shift coherence gradient sensing device and method for real-time deformation field measurement. Background Art

[0002] Coherent Gradient Sensor is a full-field interference type gradient coherent optical measurement method based on dual grating common optical path shearing interference technology. Its measurement principle is that the object wave enters the dual grating system to generate interference. Through the phase analysis of the interference fringe field before deformation (zero fringe field) and after deformation, the full-field off-plane displacement gradient data of the object surface can be solved. Due to the full-field, real-time, high-precision and high-sensitivity measurement advantages of reflective coherent gradient sensors, they are now widely used in the field of macro and micro measurements of various materials and structures.

[0003] However, the real-time measurement of deformation using coherent gradient sensors is still a cutting-edge and challenging problem. Among the technologies related to real-time measurement of coherent gradient sensing, the most direct processing method is the fringe centerline method, but the processing of interference fringe patterns by this method is greatly affected by subjective factors, which generally leads to large errors; in addition, the Fourier transform method and the sampling moiré method are also used in real-time measurement of coherent gradient sensing, but the former is usually ineffective for processing complex fringe patterns such as fringe patterns containing closed fringes, and the latter requires the artificial introduction of carrier elements in the optical path and the correction of shear, so the results are not intuitive enough and have limited applicability. Spatial phase shift technology has been used in coherent gradient sensing, but currently large spectrometers are usually used to achieve this function, making the equipment size of spatial phase shift coherent gradient sensing larger.

[0004] Therefore, how to develop a small, convenient, easy-to-operate, real-time deformation field measurement device for coherent gradient sensing measurement is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application can accurately and effectively realize the real-time and accurate measurement of the deformation field of the object to be measured, the measurement principle is simple, and the volume of the traditional coherent gradient sensor is greatly reduced, further expanding the scope of use of the coherent gradient sensor.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application proposes a polarization phase shift coherence gradient sensing device for real-time deformation field measurement, comprising:

[0007] A laser modulation component, which emits laser light to the optical surface to be measured and the reflected light beam after being reflected by the optical surface to be measured is in a collimated state;

[0008] a polarization component; the reflected light beam is reflected to the polarization component via a prism component, and the polarization component comprises a polarizer, a transmission grating group and a filter lens arranged in sequence along the optical path direction of the reflected light beam; the transmission grating group comprises a front polarization transmission grating and a rear polarization transmission grating, the reflected light beam is diffracted on the front polarization transmission grating, and the diffracted light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form an interference light beam; the interference light beam is converged into a diffraction spot via the filter lens; and

[0009] An image acquisition and processing system is arranged downstream of the filter lens along the optical path direction of the reflected light beam, and is used to acquire the diffraction spots for polarization phase shift coherence gradient sensing measurement and post-processing calculation.

[0010] In some embodiments, the laser modulation assembly includes a laser that provides laser light, and a beam expanding convex lens and a collimating convex lens that are sequentially arranged along the direction of the laser light path.

[0011] In some embodiments, the beam expanding convex lens and the collimating convex lens are both plano-convex lenses.

[0012] In some embodiments, the laser modulation assembly further includes a displacement adjustment member; the displacement adjustment member includes a slide rail extending along the laser light path direction and a slider adapted to the slide rail; the beam expanding convex lens and the collimating convex lens are respectively arranged on the slider.

[0013] In some embodiments, the prism assembly includes a beam splitter prism and a plane reflector; the reflective surface of the beam splitter prism reflects the reflected light beam again onto the plane reflector; the plane reflector is parallel to the reflective surface of the beam splitter prism to redirect the reflected light beam so that the optical path direction of the reflected light beam remains consistent with the horizontal direction.

[0014] In some embodiments, the beam splitter prism includes two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded together to form the reflective surface.

[0015] In some embodiments, the polarization component further includes a polarizer, and a rotatable polarizer is disposed between the transmission grating group and the filter lens along the optical path direction of the reflected light beam.

[0016] In some embodiments, the polarizer and the analyzer are both dichroic materials.

[0017] In some embodiments, the front polarization transmission grating and the rear polarization transmission grating are both square waveform gratings made of liquid crystal polymer, with a duty cycle of 1:1.

[0018] In some embodiments, the image acquisition and processing system includes a digital industrial polarization camera or an industrial digital camera integrated with an aperture stop and a computer image post-processing system.

[0019] In some embodiments, it also includes a support assembly and a fixing member; the support assembly includes a plurality of supports to place all components except the computer image post-processing system; the fixing member integrates all the supports onto the bottom plate base.

[0020] According to a second aspect, the present application proposes a method for real-time measurement of a deformation field, which uses the device described in any of the above embodiments to perform measurement, including the following steps:

[0021] Construct the device described in any of the above embodiments;

[0022] Adjusting the laser modulation component according to the characteristics of the optical surface to be measured, wherein the laser modulation component emits laser light to the optical surface to be measured and the reflected light beam after being reflected by the optical surface to be measured is in a collimated state;

[0023] Adjusting the clamping state of the polarization assembly so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other;

[0024] The image acquisition and processing system collects the data of the diffraction spots and performs polarization phase shift coherent gradient sensing measurement and post-processing calculation.

[0025] In some embodiments, the optical surface to be tested needs to be polished before testing, and the surface roughness after polishing is no greater than 0.02 μm.

[0026] In some embodiments, the polarizer converts the reflected light beam of natural light into linearly polarized light.

[0027] In some embodiments, the front polarization transmission grating and the rear polarization transmission grating are both transmissive liquid crystal polymer diffraction gratings with a line density of 20 line / mm.

[0028] Compared with the prior art, this application has the following advantages:

[0029] The present application utilizes the polarization phase shift theory. By replacing the sensitive element of the traditional coherent gradient sensor with a polarization component, and sequentially arranging a polarizer, a transmission grating group and a filter lens along the optical path direction of the reflected light beam, the polarization state of the two coherent light beams can be adjusted, so that the light beams passing through the transmission grating group interfere to produce deformed fringes, and polarization phase shift can be achieved according to different polarization analysis states. The principle of the real-time measurement process is simple, and the application scope of the coherent gradient sensor is further expanded.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0032] Figure 1 is a schematic structural diagram of a polarization phase shift coherence gradient sensing device in one embodiment of the present application;

[0033] Figure 2 is a light path diagram of a polarization phase shift coherence gradient sensing device in one embodiment of the present application;

[0034] Figure 3 is a spatial position relationship diagram of a partial polarization phase shift coherence gradient sensing device in one embodiment of the present application;

[0035] Figure 4 is a spatial position relationship diagram of a partial polarization phase shift coherence gradient sensing device in one embodiment of the present application;

[0036] Figure 5 It is the polarization phase-shift coherent gradient sensing zero-field fringe obtained by adjustment in one embodiment of the present application (collected by a digital industrial polarization camera).

[0037] Figure 6 It is the polarization phase shift coherent gradient sensing fringes (collected by a digital industrial polarization camera) obtained by adjusting when the surface to be measured is a spherical mirror with a curvature radius of 5m in one embodiment of the present application;

[0038] Figure 7 is a flow chart of a method for real-time measurement of deformation field in one embodiment of the present application;

[0039] In the figure, 0, bottom plate base; 1, single longitudinal mode laser; 101, laser support; 2, beam expanding convex lens; 201, beam expanding mirror frame; 202, beam expanding mirror support; 203, first slider; 204, first slide rail; 3, collimating convex lens; 301, collimating mirror frame; 302, collimating mirror support; 303, second slider; 4, optical surface to be measured; 401, mirror frame to be measured; 402, support for the surface to be measured; 403, measurement extension plate; 5, beam splitter prism; 501, beam splitter prism support; 6, plane reflector; 601, plane reflector support; 7, polarizer; 701, polarizer frame; 702, polarizer support; 8, front liquid crystal polarization Ro nchi transmission grating; 801, front grating clamping frame; 802, front grating support; 9, rear liquid crystal polarization Ronchi transmission grating; 901, rear grating clamping frame; 902, rear grating support; 10, analyzer; 1001, analyzer frame; 1002, analyzer support; 11, filter lens; 1101, filter lens frame; 1102, filter lens support; 1103, connecting plate; 12, digital industrial polarization camera or industrial digital camera; 1201, camera support; 1202, one-dimensional pitch stage; 1203, aperture stop; 1204, third slider; 1205, second slide rail; 13, computer image post-processing system. DETAILED DESCRIPTION

[0040] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0041] To achieve the above-mentioned objectives, the first aspect of the present application proposes a polarization phase-shift coherence gradient sensing device for real-time deformation field measurement, including a laser modulation component, a polarization component and an image acquisition and processing system; wherein the laser modulation component emits a laser to the optical surface 4 to be measured and the reflected light beam after reflection from the optical surface 4 to be measured is in a collimated state.

[0042] The laser modulation assembly includes a laser for providing laser light and a beam expander convex lens 2 and a collimator convex lens 3 arranged in sequence along the laser light path. In other words, the laser light path direction is Figure 1The front and back directions in the figure are consistent, where the front and back directions are as marked in the figure. In this embodiment, the laser can be a single longitudinal mode laser 1 and provide a monochromatic laser with a laser wavelength of 532.8nm, and the laser matches the wavelength limit of each optical element in the device and the optical surface 4 to be measured; the laser emitted by the laser is directed toward the optical surface 4 to be measured, where the direction from the laser toward the optical surface 4 to be measured is the laser light path direction, that is, the laser emits the laser from back to front. In this embodiment, after the laser emits the laser, the laser passes through the beam expanding convex lens 2 and the collimating convex lens 3 in sequence along the laser light path direction and reaches the optical surface 4 to be measured. The reflected light beam of the laser after being reflected by the optical surface 4 to be measured is in a collimated state; wherein the beam expanding convex lens 2 and the collimating convex lens 3 are both plano-convex lenses, and the materials of the beam expanding convex lens 2 and the collimating convex lens 3 in the example are both optical glass K9.

[0043] It should be explained that in order to ensure that the reflected light beam of the laser after being reflected by the optical surface 4 to be measured is in a collimated state, the optical surface 4 to be measured needs to be precisely polished, and the surface roughness after polishing should be guaranteed to be no greater than 0.02μm to achieve mirror reflection.

[0044] In this embodiment, the reflected light beam is reflected to the polarization component through the prism component, and the polarization component includes a polarizer 7, a transmission grating group and a filter lens 11 arranged in sequence along the optical path direction of the reflected light beam; the transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating, the reflected light beam is diffracted on the front polarization transmission grating, and the diffracted light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form an interference light beam; the interference light beam is converged into a diffraction spot through the filter lens 11; the material of the example filter lens 11 is optical glass K9.

[0045] Among them, the optical path direction of the reflected light beam is Figure 1 The front-to-back direction in is consistent, where the front-to-back direction is Figure 1 As shown. The laser is reflected by the optical surface 4 to be measured, wherein the reflected light beam is then reflected to the polarization component through the prism assembly, and the direction of the reflected light beam incident on the polarization component is from front to back, so the prism assembly only changes the extension direction of the reflected light beam, so that the reflected light beam is incident on the polarization component in a horizontal direction. In this embodiment, the polarization component includes a polarizer 7, a transmission grating group and a filter lens 11 arranged in sequence along the optical path direction of the reflected light beam; wherein the reflected light beam propagates to the polarizer 7 and is converted into linearly polarized light transmission, wherein the polarizer 7 is a dichroic material, which can convert the natural light reflected from the surface of the object into linearly polarized light transmission. The transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating, and the linearly polarized light is diffracted on the front polarization transmission grating, and the diffracted light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form an interference light beam; the interference light beam is converged into a diffraction spot through the filter lens 11.

[0046] The front polarization transmission grating and the rear polarization transmission grating of the example are both square waveform gratings made of liquid crystal polymer, with a duty cycle of 1:1; for example, the front polarization transmission grating is the front liquid crystal polarization Ronchi transmission grating 8, and the linearly polarized light passing through the front liquid crystal polarization Ronchi transmission grating 8 is incident perpendicular to the grating plane (that is, the incident angle through the grating is 0 degrees). The linearly polarized light is diffracted on the front polarization transmission grating, and the diffracted light beam then reaches the rear polarization transmission grating; the rear polarization transmission grating can be the rear liquid crystal polarization Ronchi transmission grating 9, and the diffracted light beam reaches the rear liquid crystal polarization Ronchi transmission grating 9 and undergoes a second diffraction, and the diffracted light beams interfere with each other. After passing through the rear liquid crystal polarization Ronchi transmission grating 9, the interference light beam can directly reach the filter lens 11, and the interference light beam is converged into a diffraction spot and enters the image acquisition and processing system, where the optical path diagram of the laser in the polarization phase shift coherence gradient sensor device is shown as follows. Figure 2 shown.

[0047] The image acquisition and processing system in this embodiment is arranged downstream of the filter lens 11 along the optical path direction of the reflected light beam, so as to collect diffraction spots for polarization phase shift coherent gradient sensing measurement and post-processing calculation. The image acquisition and processing system includes a digital industrial polarization camera or industrial digital camera 12 integrated with an aperture diaphragm 1203 and a computer image post-processing system 13. That is, the lens of the digital industrial polarization camera or industrial digital camera 12 of the present application is integrated with an aperture diaphragm 1203; the interference light beam is converged into a diffraction spot and enters the digital industrial polarization camera or industrial digital camera 12 integrated with an aperture diaphragm 1203. After the digital industrial polarization camera or industrial digital camera 12 integrated with an aperture diaphragm 1203 collects the image, the collected information is sent to the computer image post-processing system 13 for further CGS calculation and post-processing.

[0048] This application utilizes the characteristics of interfering polarized light and the characteristics of the CGS system, and adjusts the polarization state of the interfering light beam through a polarizer 7 and a polarization component to obtain spatial phase shift fringes, and can choose to perform time phase shift or spatial phase shift technology for solving. The principle is simple and the operation is convenient. It solves the technical problem that the CGS method cannot perform high-precision real-time intuitive measurement, and expands the measurement range. In addition, this application is suitable for real-time measurement of deformation of various optical surfaces that can be mirror-reflected, and realizes the requirements of in-situ real-time measurement of industrial surfaces with high efficiency, non-destructiveness, easy operation, and wide application. Therefore, compared with the related art, this application only adds a polarizer 7 and a polarization component, and replaces the original sensitive element in the related art with a polarization optical element to achieve real-time measurement of the optical surface 4 to be measured. It has a simple structure, a concise principle, and does not require changing the original measurement system optical path layout. It is easy to operate and has a low economic cost for transformation.

[0049] In some embodiments, the laser modulation assembly further includes a displacement adjustment member; the displacement adjustment member includes a slide rail extending along the laser light path direction and a slider adapted to the slide rail; the beam expanding convex lens 2 and the collimating convex lens 3 are respectively arranged on the slider.

[0050] The displacement adjustment member includes a slide rail and a slider extending along the laser light path; the sliders are multiple and matched with the slide rails, and the beam expander convex lens 2 and the collimator convex lens 3 are respectively arranged on the sliders, and the positions of the beam expander convex lens 2 and the collimator convex lens 3 can be adjusted by moving the sliders on the slide rails. Figure 4 As shown, considering that the beam expanding convex lens 2 and the collimating convex lens 3 need to be translated according to the test requirements in order to modulate the laser emitted by the single longitudinal mode laser 1, a first slide rail 204 is provided along the front-to-back direction, and a first slider 203 and a second slider 303 are sequentially provided on the first slide rail 204, the beam expanding convex lens 2 is provided on the first slider 203; the collimating convex lens 3 is provided on the second slider 303; when it is necessary to modulate the laser according to the test requirements, the beam expanding convex lens 2 and the collimating convex lens 3 are translated accordingly by the first slider 203 and the second slider 303, and it is ensured that the centers of the beam expanding convex lens 2 and the collimating convex lens 3 are at the same horizontal height.

[0051] In addition, in some schemes, in order to fix the beam expander convex lens 2 and the collimator convex lens 3, a beam expander support 202 is arranged on the first slider 203, and the beam expander convex lens 2 is fixedly arranged on the beam expander frame 201 at the top of the beam expander support 202; a collimator support 302 is arranged on the second slider 303, and the collimator convex lens 3 is fixedly arranged on the collimator frame 301 at the top of the collimator support 302.

[0052] In some embodiments, the prism assembly includes a beam splitter prism 5 and a plane reflector 6; the reflective surface of the beam splitter prism 5 reflects the reflected light beam again onto the plane reflector 6; the plane reflector 6 is parallel to the reflective surface of the beam splitter prism 5 to redirect the reflected light beam so that the optical path direction of the reflected light beam remains consistent with the horizontal direction.

[0053] The prism assembly includes a beam splitter prism 5 and a plane reflector 6, that is, in the front-to-back direction, the beam splitter prism 5 is arranged between the collimating convex lens 3 and the optical surface to be measured 4, and the beam splitter prism 5 includes two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded to form a reflecting surface. In other words, the inclined surfaces of the two right-angle optical quartz glass prisms are bonded as follows: Figure 4As shown, the laser light passing through the collimating convex lens 3 passes through the beam splitter prism 5 and reaches the optical surface 4 to be measured. The beam splitter prism 5 can reflect the reflected light beam reflected by the optical surface 4 to be measured to the plane reflector 6 for deflection. The reflected light beam is reflected by the plane reflector 6, and the optical path is changed to propagate in the front-back direction. The material of the plane reflector 6 is optical glass K9, and a layer of reinforced aluminum reflective film is vacuum-deposited on the surface of the plane reflector 6. The laser light passes through the laser modulation component and the beam splitter prism 5 and is irradiated on the optical surface 4 to be measured and reflected. It is nearly collimated and reaches the beam splitter prism 5 again. The beam splitter prism 5 reflects the reflected light beam to the plane reflector 6 for deflection, and propagates to the polarizer 7 and converts it into linear polarized light for transmission. The polarizer 7 is fixed on the polarizer support 702 through the polarizer frame 701.

[0054] In some embodiments, the polarization component further includes a polarizer 10 , and a rotatable polarizer 10 is disposed between the transmission grating group and the filter lens 11 along the optical path direction of the reflected light beam.

[0055] As shown in the above content, the interference beam is converged into a diffraction spot and then enters the digital industrial polarization camera or industrial digital camera 12 with integrated aperture diaphragm 1203. After the digital industrial polarization camera or industrial digital camera 12 with integrated aperture diaphragm 1203 collects the image, the collected information is sent to the computer image post-processing system 13 for further CGS calculation and post-processing. However, in this embodiment, the polarization component also includes a polarizer 10 such as Figure 2 and Figure 3 As shown, in the front-to-back direction, the analyzer 10 is located between the rear polarization transmission grating and the filter lens 11, which is a dichroic material. The interference light passes through the rear liquid crystal polarization Ronchi transmission grating 9 and can reach the filter lens 11 through the analyzer 10. The interference light beam is converged into a diffraction spot and enters the image acquisition and processing system containing an industrial digital camera.

[0056] For example, a rotatable analyzer 10 can be arranged between the liquid crystal polarization Ronchi transmission grating group and the filter lens 11 along the front-to-back direction. The analyzer 10 is fixed on the analyzer support 1002 via the analyzer frame 1001. An image acquisition and processing system including an industrial digital camera is arranged behind the filter lens 11 along the optical path direction to realize time phase shift, which is convenient for analyzing the distribution morphology of stripes. Alternatively, an image acquisition and processing system including a digital industrial polarization camera including an integrated analyzer 10 is directly arranged behind the filter lens 11 along the optical path direction to realize spatial phase shift.

[0057] like Figure 5 The polarization phase shift coherence gradient sensing zero field fringes are collected by a digital industrial polarization camera in this embodiment under the condition that the optical surface 4 to be measured is flat. Figure 5It can be seen that the zero field adjustment obtains a relatively perfect near-zero fringe field, but due to the half-wave delay of the liquid crystal polymer polarization grating, a fringe will appear in the zero field, which needs to be corrected in the post-processing process. The subsequent method is similar to the existing CGS method. Figure 6 The figure shows the data collected by a digital industrial polarization camera corresponding to the zero field adjustment. Figure 5 The obtained polarization phase shift coherent gradient sensing measurement fringes of the concave spherical surface with a curvature radius of 5 m. That is, this embodiment solves the technical problem that the traditional CGS method is difficult to perform real-time high-precision measurement, expands the application scope of the CGS method, and has strong operability.

[0058] In some embodiments, a support assembly and a fixing member are also included; the support assembly includes a plurality of supports to place all components except the computer image post-processing system 13; the fixing member integrates all supports onto the bottom plate base 0.

[0059] For example Figure 1 All elements in the present application are integrated onto the bottom plate base 0 through supporting components and fixing parts; for example, the laser modulation component includes a laser support 101 disposed on the bottom plate base 0, on which a single longitudinal mode laser 1 for providing a laser light source is fixedly disposed; and in order to ensure that the optical surface 4 to be measured, the beam expanding convex lens 2, and the collimating convex lens 3 are on the same horizontal plane, a measurement extension plate 403 is disposed on the bottom plate base 0 at a position corresponding to the optical surface 4 to be measured, which is disposed corresponding to the first slide rail, and a surface support 402 to be measured is disposed on the measurement extension plate 403, and a mirror frame 401 for fixing the surface to be measured is disposed on the surface support 402. A beam splitter prism support 501 for fixing the beam splitter prism 5 is disposed on the bottom plate base 0, and after the beam splitter prism support 501 raises the horizontal height of the beam splitter prism 5, it is ensured that the laser modulated by the laser modulation component can completely pass through the beam splitter prism 5. A front grating support 802 and a rear grating support 902 for fixing the front liquid crystal polarization Ronchi transmission grating 8 and the rear liquid crystal polarization Ronchi transmission grating 9 are respectively arranged on the bottom plate base 0; a front grating clamping frame 801 for clamping the front liquid crystal polarization Ronchi transmission grating 8 is fixedly arranged on the front grating support 802; and a rear grating clamping frame 901 for clamping the rear liquid crystal polarization Ronchi transmission grating 9 is arranged on the rear grating support 902.

[0060] In addition, a connecting plate 1103 is provided on the bottom plate base 0, and a filter lens support 1102 for fixing the filter lens 11 is fixedly provided on the connecting plate 1103, and a filter lens frame 1101 installed on the top thereof is used to install the filter lens 11, and a second slide rail 1205 is fixedly provided on the connecting plate 1103, and a one-dimensional pitch platform 1202 is slidably connected to the second slide rail 1205 through a third slider 1204, and a camera support 1201 is fixedly provided on the one-dimensional pitch platform 1202, and the camera support 1201 is fixedly connected to a digital industrial polarization camera or an industrial digital camera 12 with an integrated aperture diaphragm 1203.

[0061] It should be noted that the wavelength limit of each optical element and the surface to be measured in the system should be set to match the monochromatic laser light source emitted by the single longitudinal mode laser 1, and the laser support 101, the beam expander support 202, the first slider 203, the first slide rail 204, the collimator support 302, the second slider 303, the surface to be measured support 402, the beam splitter prism support 501, the plane reflector support 601, the front grating clamping frame 801, the rear grating clamping frame 901, the connecting plate 1103, the camera support 1201, and the one-dimensional pitch table 1202 are all made of 304 stainless steel, and the surfaces of the first slider 203, the first slide rail 204, the second slider 303, the front grating clamping frame 801, the rear grating clamping frame 901, the connecting plate 1103, the one-dimensional pitch table 1202, the third slider 1204, and the second slide rail 1205 are all treated with black oxidation.

[0062] According to the second aspect, the present application proposes a method for real-time measurement of deformation field. Figure 7 , using the device in any of the above embodiments to perform measurement, comprising the following steps:

[0063] S1: Build the device in any of the above embodiments;

[0064] S2: adjusting the laser modulation component according to the characteristics of the optical surface 4 to be measured, the laser modulation component emits a laser to the optical surface 4 to be measured, and the reflected light beam after being reflected by the optical surface 4 to be measured is in a collimated state;

[0065] S3: adjusting the clamping state of the polarization assembly so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other;

[0066] S4: The image acquisition and processing system collects the diffraction spot data and performs polarization phase shift coherent gradient sensing measurement and post-processing calculation.

[0067] Among them, the polarization phase shift coherent gradient sensing device for real-time deformation field measurement shown in the figure is constructed, which includes a bottom plate base 0, on which a laser modulation component is arranged; wherein the beam splitter prism 5 can reflect the reflected light beam of the optical surface 4 to be measured to the plane reflector 6, wherein the optical surface 4 to be measured needs to be polished before detection, and the surface roughness after polishing is not greater than 0.02μm; the plane reflector 6 turns the reflected light beam to the polarizer 7; along the front-to-back direction, a transmission grating group is arranged behind the polarizer 7, and a filter lens 11 is arranged behind the transmission grating group; a rotatable polarizer 10 can be arranged between the transmission grating group and the filter lens 11, and an image acquisition and processing system containing an industrial digital camera is arranged behind the filter lens 11 along the optical path direction to realize time phase shift, which is convenient for analyzing the distribution morphology of stripes; it can also directly correspond to the image acquisition and processing system of a digital industrial polarization camera containing an integrated polarizer 10 arranged behind the filter lens 11 along the optical path direction to realize spatial phase shift. The polarizer 7 converts the reflected light beam of natural light into linearly polarized light; the transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating; the front polarization transmission grating and the rear polarization transmission grating are both transmission liquid crystal polymer diffraction gratings with a line density of 20 line / mm.

[0068] After the polarization phase shift coherence gradient sensing device for real-time deformation field measurement is built, the positions of the beam expander convex lens 2 and the collimator convex lens 3 on the optical axis are adjusted according to the characteristics of the optical surface 4 to be measured, so that the light beam reflected by the optical surface 4 to be measured is in a collimated state; and the clamping state of the front polarization transmission grating and the rear polarization transmission grating is adjusted so that the grating lines in two directions of the two gratings are parallel to each other; at the same time, the digital industrial polarization camera with integrated aperture diaphragm 1203 and analyzer 10 is turned on to start data collection, and the coherence gradient sensing polarization phase shift measurement and post-processing calculation are further performed through the computer image post-processing system 13. Or in the case of an industrial digital camera with integrated aperture diaphragm 1203, the camera is turned on and the analyzer 10 is rotated to start data collection, and the coherence gradient sensing polarization phase shift measurement and post-processing calculation are further performed through the computer image post-processing system 13.

[0069] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0070] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0072] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A polarization phase shift coherence gradient sensing device for real-time deformation field measurement, characterized in that: include A laser modulation component, which emits laser light to the optical surface to be measured and the reflected light beam after being reflected by the optical surface to be measured is in a collimated state; A polarization component; the reflected light beam is reflected by the prism component, and its optical path direction remains unchanged and is incident on the polarization component in a horizontal direction, which includes a polarizer, a transmission grating group and a filter lens arranged in sequence along the optical path direction of the reflected light beam; the transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating, the reflected light beam is diffracted on the front polarization transmission grating, and the diffracted light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form an interference light beam; the interference light beam is converged into a diffraction spot through the filter lens; as well as An image acquisition and processing system is arranged downstream of the filter lens along the optical path direction of the reflected light beam, and is used to acquire the diffraction spots for polarization phase shift coherence gradient sensing measurement and post-processing calculation.

2. The device according to claim 1, characterized in that The laser modulation component comprises a laser for providing laser light, and a beam expanding convex lens and a collimating convex lens which are sequentially arranged along the direction of the laser light path.

3. The device according to claim 2, characterized in that The beam expanding convex lens and the collimating convex lens are both plano-convex lenses.

4. The device according to claim 2 or 3, characterized in that The laser modulation assembly also includes a displacement adjustment member; the displacement adjustment member includes a slide rail extending along the laser light path direction and a slider adapted to the slide rail; the beam expanding convex lens and the collimating convex lens are respectively arranged on the slider.

5. The device according to claim 4, characterized in that The prism assembly includes a beam splitter prism and a plane reflector; the reflective surface of the beam splitter prism reflects the reflected light beam again onto the plane reflector; the plane reflector is parallel to the reflective surface of the beam splitter prism to redirect the reflected light beam so that the optical path direction of the reflected light beam is consistent with the horizontal direction.

6. The device according to claim 5, characterized in that The beam splitter prism includes two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded together to form the reflecting surface.

7. The device according to claim 5, characterized in that The polarization component further comprises a polarizer, and a rotatable polarizer is arranged between the transmission grating group and the filter lens along the optical path direction of the reflected light beam.

8. The device according to claim 7, characterized in that The polarizer and the analyzer are both made of dichroic materials.

9. The device according to claim 4, characterized in that The front polarization transmission grating and the rear polarization transmission grating are both square wave gratings made of liquid crystal polymer, and the duty ratio is 1:

1.

10. The device according to claim 4, characterized in that The image acquisition and processing system comprises a digital industrial polarization camera or an industrial digital camera integrated with an aperture stop and a computer image post-processing system.

11. The device according to claim 10, characterized in that It also includes a support assembly and a fixing member; the support assembly includes a plurality of supports to place all components except the computer image post-processing system; the fixing member integrates all the supports onto the bottom plate base.

12. A method for real-time measurement of deformation field, characterized in that: Measuring using the device described in any one of claims 1 to 11 comprises the following steps: Constructing the device described in any one of claims 1 to 11; Adjusting the laser modulation component according to the characteristics of the optical surface to be measured, wherein the laser modulation component emits laser light to the optical surface to be measured and the reflected light beam after being reflected by the optical surface to be measured is in a collimated state; Adjusting the clamping state of the polarization assembly so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other; The image acquisition and processing system collects the data of the diffraction spots and performs polarization phase shift coherent gradient sensing measurement and post-processing calculation.

13. The method according to claim 12, characterized in that The optical surface to be tested needs to be polished before testing, and the surface roughness after polishing is not greater than 0.02 μm.

14. The method according to claim 12, characterized in that The polarizer converts the reflected light beam of natural light into linearly polarized light.

15. The method according to claim 12, characterized in that The front polarization transmission grating and the rear polarization transmission grating are both transmission type liquid crystal polymer diffraction gratings with a line density of 20 line / mm.

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