Device and method for testing wavefront phase of light beam
By designing a beam wavefront phase test device including a dual light source and a dot matrix pattern card, the problems of small target surface, low accuracy and high cost in the prior art wavefront sensor are solved, and high precision and low cost beam wavefront phase test is realized.
Patent Information
- Application Number
- CN202411589382.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2025-03-25
AI Technical Summary
In the prior art, the wavefront sensor target surface used for wavefront phase testing is generally small, has low accuracy and is costly to use.
A beam wavefront phase testing device is designed, including a first light source, a first dot matrix card, a spectrometer element, a product to be tested, an imaging module, a test camera, a product vehicle, a second light source, a second dot matrix card and a control system. Through the dual light source design and the use of dot matrix diagram cards, parallel dot matrix beams are formed, the number of light spots received by the test camera is increased, and the wavefront phase is calculated through the fitting method.
High-precision and low-cost beam wavefront phase testing is realized, which improves testing accuracy and efficiency and reduces equipment costs.
Smart Images
Figure CN119688090A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of light beam wavefront phase testing, and in particular to a light beam wavefront phase testing device and method. Background Art
[0002] The wavefront information of a light wave describes the phase distribution of the light wave, that is, the phase of the light wave arriving at different points in space. The phase of a light wave is a physical quantity that describes the vibration state of the light wave at different positions in space. Wavefront phase testing has a wide range of applications in many fields. In optical measurement and processing, it can detect lens processing accuracy and measure optical parameters; in optical imaging, wavefront sensors help correct aberrations and improve imaging quality.
[0003] In the prior art, the target surface of the wavefront sensor used for wavefront phase testing is generally small, the accuracy is low, and the cost of use is high. Summary of the invention
[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a light beam wavefront phase testing device and method, which can realize high-precision and low-cost light beam wavefront phase testing.
[0005] On the one hand, an embodiment of the present invention proposes a light beam wavefront phase test device, including a first light source, a first dot pattern card, a spectroscopic element, a product to be tested, an imaging module, a test camera, a product carrier, a second light source, a second dot pattern card, and a control system. The first light source, the first dot pattern card, the spectroscopic element, the product to be tested, the imaging module, and the test camera are sequentially arranged along the propagation direction of the light path and kept coaxial; the second light source is arranged on one side of the spectroscopic element; the second dot pattern card is arranged between the spectroscopic element and the second light source; the control system is electrically connected to the first light source, the second light source, and the test camera respectively;
[0006] Among them, the light emitted by the first light source passes through the first dot matrix card, the spectroscopic element, the product to be tested and the imaging module in sequence, and enters the test camera; the light emitted by the second light source passes through the second dot matrix card and reaches the spectroscopic element, and is refracted by the spectroscopic element to the product to be tested, and after passing through the product to be tested and the imaging module, enters the test camera.
[0007] According to some embodiments of the present invention, the first dot matrix card and the second dot matrix card are respectively provided with dot holes arranged at equal intervals.
[0008] According to some embodiments of the present invention, the imaging module includes an objective lens and a sleeve tube lens that are fixedly connected.
[0009] According to some embodiments of the present invention, the light beam wavefront phase testing device also includes a first electric adjustment device, a second electric adjustment device, a third electric adjustment device and a fourth electric adjustment device, and the first electric adjustment device, the second electric adjustment device, the third electric adjustment device and the fourth electric adjustment device are all electrically connected to the control system, the first electric adjustment device is used to adjust the position of the first light source, the second electric adjustment device is used to adjust the position of the second light source, the third electric adjustment device is used to adjust the position of the product carrier, and the fourth electric adjustment device is used to adjust the position of the imaging module and the test camera.
[0010] According to some embodiments of the present invention, the first light source and / or the second light source can emit parallel light beams of multiple different colors.
[0011] On the other hand, the present invention further provides a light beam wavefront phase testing method, which is applied to the light beam wavefront phase testing device provided by the present invention, and the testing method comprises:
[0012] Acquire a first system spot diagram and a second system spot diagram of the light beam wavefront phase testing device; the first system spot diagram represents the light emitted by the first light source, and after passing through the first dot pattern card, the spectroscopic element and the imaging module to reach the testing camera, the spot image obtained by the testing camera; the second system spot diagram represents the light emitted by the second light source, and after passing through the second dot pattern card, the spectroscopic element and the imaging module to reach the testing camera, the spot image obtained by the testing camera;
[0013] Acquire a first product dot matrix spot diagram and a second product dot matrix spot diagram of the light beam wavefront phase testing device; the first product dot matrix spot diagram represents the light emitted by the first light source, and after passing through the first dot matrix card, the spectroscopic element, the product to be tested and the imaging module to reach the test camera, the spot image obtained by the test camera; the second product dot matrix spot diagram represents the light emitted by the second light source, and after passing through the second dot matrix card, the spectroscopic element, the product to be tested and the imaging module to reach the test camera, the spot image obtained by the test camera;
[0014] Calculating gradient information according to the first system spot diagram, the second system spot diagram, the first product dot matrix spot diagram, and the second product dot matrix spot diagram;
[0015] The gradient information is converted into wavefront phase using a fitting method.
[0016] According to some embodiments of the present invention, the step of obtaining a first system spot diagram and a second system spot diagram of the light beam wavefront phase testing device includes:
[0017] Removing the product carrier and the product to be tested so that they are not in the optical path;
[0018] The control system lights up the first light source, so that the light emitted by the first light source is converted into a first parallel dot matrix light beam through the first dot matrix card;
[0019] The first parallel dot matrix light beam passes through the imaging module and the test camera in sequence, and the test camera obtains a first system spot diagram;
[0020] The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera obtains a plurality of first system spot patterns corresponding to different positions;
[0021] The control system turns off the first light source and turns on the second light source, so that the light emitted by the second light source is converted into a second parallel dot matrix light beam through the second dot matrix card;
[0022] The second parallel dot matrix light beam passes through the beam splitter element, is refracted by the beam splitter element, and then passes through the imaging module to reach the test camera, and the test camera obtains a second system spot diagram;
[0023] The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera acquires the second system spot diagram at multiple different positions.
[0024] According to some embodiments of the present invention, the step of obtaining a first product dot-matrix spot pattern and a second product dot-matrix spot pattern of the light beam wavefront phase testing device includes:
[0025] Put the product to be tested on the product carrier, and the control system controls the third electric adjustment device to move the product carrier to the test position and light up the first light source;
[0026] The light emitted by the first light source is converted into a first parallel dot matrix light beam through the first dot matrix card;
[0027] After being transmitted by the beam splitter, the first parallel dot matrix light beam sequentially passes through the product to be tested and the imaging module to reach the test camera, so that the test camera obtains the dot matrix light spot image of the first product;
[0028] The control system controls the fourth electric adjustment device to drive the imaging module and the test camera to move forward and backward, so that the test camera acquires a plurality of first product dot matrix spot images;
[0029] The control system turns off the first light source and turns on the second light source;
[0030] The light emitted by the second light source is converted into a second parallel dot matrix light beam through a second dot matrix card;
[0031] The second parallel dot matrix light beam passes through the beam splitter element, is refracted by the beam splitter element, and then sequentially passes through the product to be tested and the imaging module to reach the test camera, so that the test camera obtains the dot matrix light spot image of the second product;
[0032] The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera obtains the second product dot matrix spot images at multiple different positions.
[0033] According to some embodiments of the present invention, the calculating gradient information includes:
[0034] The test camera transmits a plurality of the first system spot patterns, a plurality of the second system spot patterns, a plurality of the first product dot matrix spot patterns, and a plurality of the second product dot matrix spot patterns to the control system;
[0035] The control system acquires the coordinate offset of the light spot of each first system light spot pattern and the corresponding first product dot light spot pattern to obtain first gradient information;
[0036] The control system acquires the coordinate offset of the light spot of each second system light spot pattern and the corresponding second product dot matrix light spot pattern to obtain second gradient information.
[0037] According to some embodiments of the present invention, converting the gradient information into a wavefront phase using a fitting method comprises:
[0038] The control system converts the gradient information into a wavefront phase by a least squares fitting method, and the calculation formula of the least squares method is:
[0039] W(x,y)=∫g(x)dx+∫g(y)dy
[0040] W(x, y) is the phase distribution of the entire wavefront, g(x) is the gradient information in the x direction, and g(y) is the gradient information in the y direction.
[0041] The light beam wavefront phase testing device and method according to the embodiments of the present invention have at least the following beneficial effects:
[0042] The device is provided with a first light source and a second light source. The first light source and the second light source form parallel dot matrix beams through the corresponding first dot matrix card and the second dot matrix card, which increases the number of light spots received by the test camera and can perform time-sharing imaging to improve the accuracy of the beam wavefront phase test. Before the product to be tested is placed, the imaging received by the test camera is the system spot diagram. When the product to be tested is placed without changing the light source and the focal length of the objective lens is adjusted, the test camera receives the product spot diagram of the corresponding light source.
[0043] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:
[0045] Figure 1 A structural diagram of a light beam wavefront phase testing device according to an embodiment of the present invention;
[0046] Figure 2 A flow chart of the steps of a method for testing a light beam wavefront phase according to an embodiment of the present invention;
[0047] Reference numerals:
[0048] A first light source 101, a second light source 102, a first dot matrix card 201, a second dot matrix card 202, a spectroscopic element 300, a product to be tested 401, a product carrier 402, a test camera 500, an imaging module 600, a first electric adjustment device 701, a second electric adjustment device 702, a third electric adjustment device 703, a fourth electric adjustment device 704, and a control system 800. DETAILED DESCRIPTION
[0049] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.
[0050] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0051] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.
[0052] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.
[0053] Reference Figure 1 The present invention proposes a light beam wavefront phase test device, comprising a first light source 101, a first dot pattern card 201, a spectroscopic element 300, a product to be tested 401, an imaging module 600, a test camera 500, a product carrier 402, a second light source 102, a second dot pattern card 202 and a control system 800. The first light source 101, the first dot pattern card 201, the spectroscopic element 300, the product to be tested 401, the imaging module 600 and the test camera 500 are sequentially arranged along the propagation direction of the light path and kept coaxial; the second light source 102 is arranged on one side of the spectroscopic element 300; the second dot pattern card 202 is arranged between the spectroscopic element 300 and the second light source 102; the control system 800 is electrically connected to the first light source 101, the second light source 102 and the test camera 500 respectively;
[0054] Among them, the light emitted by the first light source 101 passes through the first dot matrix card 201, the spectroscopic element 300, the product to be tested 401 and the imaging module 600 in sequence, and enters the test camera 500; the light emitted by the second light source 102 passes through the second dot matrix card 202 and reaches the spectroscopic element 300, and is refracted by the spectroscopic element 300 to the product to be tested 401, and after passing through the product to be tested 401 and the imaging module 600, enters the test camera 500.
[0055] It should be noted that the light splitting element 300 may be a light splitting device such as a light splitting prism or a grating, for splitting the light. The test camera 500 may be a CCD (charge coupled device) camera or a CMOS (complementary metal oxide semiconductor) camera.
[0056] Reference Figure 1In this example, the first light source 101 and the second light source 102 form parallel dot matrix light beams through the corresponding first dot matrix card 201 and the second dot matrix card 202, which can increase the number of light spots received by the test camera 500, that is, it can calculate the gradient information of more light spots, thereby fitting a more accurate light beam wavefront phase. The design of dual light sources can perform time-sharing imaging and improve the accuracy of light beam wavefront phase testing.
[0057] The product to be tested 401 includes a lens, and the product carrier 402 is used to carry the product to be tested 401. When obtaining the system spot pattern, the product carrier 402 will move the product to be tested 401 so that the product to be tested 401 is not in the light path; when obtaining the product dot matrix spot pattern, the product carrier 402 needs to move the product to be tested 401 to the test position so that the product to be tested 401 is in the light path.
[0058] The control system 800 includes three subsystems: a light source driving system, an electric adjustment device control system, and an image collection and processing system. At the same time, the present invention also includes a first electric adjustment device 701 , a second electric adjustment device 702 , a third electric adjustment device 703 , and a fourth electric adjustment device 704 .
[0059] The light source driving system is used to control the switching of the first light source 101 and the second light source 102 and the switching of the light beam color; the electric adjustment device control system controls the first electric adjustment device 701, the second electric adjustment device 702 and the third electric adjustment device 703 to move the positions of the first light source, the second light source and the product carrier respectively, so that the system optical path is coaxial and the test accuracy is improved. At the same time, it also controls the fourth electric adjustment device 704 to move forward and backward to obtain the product spot diagram and the system spot diagram at different distances. The image collection and processing system processes, analyzes and calculates the product spot diagram and the system spot diagram transmitted by the test camera 500.
[0060] At the same time, the present invention can automatically perform system calibration, and the control system 800 adjusts the first light source 101 and the second light source 102 respectively according to the center position of the light beam dot matrix obtained by the test camera 500 to make the system optical path coaxial, thereby saving equipment debugging time. For example: the test camera 500 will feed back the collected spot image to the control system 800, and the image collection and processing system of the control system 800 will process and calculate the input spot image information, calculate the coordinate position of the center of mass of the spot, and input the coordinate position information to the electric adjustment device control system of the control system 800. When the coordinate position of the center of mass of the spot deviates, that is, it is judged that the optical path is not in a coaxial state, the electric adjustment device control system of the control system 800 will control the corresponding components to adjust according to this information until each optical path is in a coaxial state.
[0061] Furthermore, in some embodiments of the present invention, the first dot matrix card 201 and the second dot matrix card 202 are respectively provided with equally spaced dot holes, which respectively convert the light emitted by the first light source 101 and the second light source 102 into parallel dot matrix light beams, thereby increasing the number of light spots received by the test camera 500 in the light spot diagram and improving the test accuracy.
[0062] Furthermore, in some embodiments of the present invention, the imaging module 600 includes an objective lens and a sleeve tube lens that are fixedly connected. The objective lens is installed at the front end of the sleeve tube lens, responsible for receiving and focusing the light, and the sleeve tube lens supports the objective lens, maintains the light path so that the light reaches the test camera 500 smoothly, and improves the acquisition accuracy of the system spot diagram or the product spot diagram.
[0063] Furthermore, in some embodiments of the present invention, the light beam wavefront phase testing device also includes a first electric adjustment device 701, a second electric adjustment device 702, a third electric adjustment device 703 and a fourth electric adjustment device 704. The first electric adjustment device 701, the second electric adjustment device 702, the third electric adjustment device 703 and the fourth electric adjustment device 704 are all electrically connected to the control system 800. The first electric adjustment device 701 is used to adjust the position of the first light source 101, the second electric adjustment device 702 is used to adjust the position of the second light source 102, and the third electric adjustment device 703 is used to adjust the position of the product carrier 402, so that the first light source 101, the product to be tested 401, the imaging module 600 and the test camera 500 maintain a coaxial optical path, thereby improving the test accuracy, and the light emitted by the second light source 102 is refracted by the spectroscopic element 300 to form a coaxial optical path with the product to be tested 401, the imaging module 600 and the test camera 500. The fourth electric adjustment device 704 is used to adjust the positions of the imaging module 600 and the test camera 500. The control system 800 controls the fourth electric adjustment device 704 to move forward and backward to obtain spot diagrams at multiple different positions, thereby calculating multiple gradient information to improve test accuracy.
[0064] It should be noted that the first electric adjustment device 701 , the second electric adjustment device 702 , the third electric adjustment device 703 and the fourth electric adjustment device 704 may adopt a structure capable of adjusting the position, such as a multi-axis adjustment mechanical arm or a screw transmission device.
[0065] Furthermore, in some embodiments of the present invention, the first light source 101 and / or the second light source 102 can emit parallel light beams of multiple different colors. Light beams of different colors correspond to different wavelengths, and selecting light sources of different colors can expand the spectrum range of the test and improve the test accuracy.
[0066] According to the light beam wavefront phase testing device of the present invention, the dual light source design can perform time-sharing imaging and improve the accuracy of light beam wavefront phase testing; during the test, the control system 800 can control the light source to switch to different colors of light, thereby expanding the spectral range of the test and improving the test accuracy.
[0067] At the same time, the test camera 500 can also monitor the coaxial state of the optical path of the system, and feed back the collected spot image information to the image collection and processing system of the control system 800 to calculate the spot centroid position and judge the coaxial state of the optical path. If the optical path is not in the coaxial state, the electric adjustment device control system of the control system 800 will control the corresponding electric adjustment device to move the corresponding component until the optical path is in the coaxial state, so that the error in the light beam wavefront phase test process is reduced; in addition, the control system 800 can be set to periodically self-check, by regularly lighting up the first light source 101 and the second light source 102 to calibrate the system, and automatically adjust the first light source 101, the second light source 102 and the position in the device, so as to ensure the stability and accuracy of the test.
[0068] On the other hand, in some embodiments of the present invention, the present invention further provides a light beam wavefront phase testing method, which is applied to the light beam wavefront phase testing device provided by the present invention, such as Figure 2 As shown, the test methods include:
[0069] Step S100: obtaining the first system spot diagram and the second system spot diagram of the light beam wavefront phase testing device; the first system spot diagram represents the light emitted by the first light source 101, and the spot image obtained by the test camera 500 after passing through the first dot pattern card 201, the spectroscopic element 300 and the imaging module 600 to reach the test camera 500; the second system spot diagram represents the light emitted by the second light source 102, and the spot image obtained by the test camera 500 after passing through the second dot pattern card 202, the spectroscopic element 300 and the imaging module 600 to reach the test camera 500; the first system spot diagram and the second system spot diagram can obtain the coordinate position of each light spot before the product to be tested is placed, and can be combined with the first product dot pattern spot diagram and the second product dot pattern spot diagram of the next step S200 to calculate the gradient information of multiple light spots, so as to provide more data for the subsequent step S400 to use the least squares method to fit the wavefront phase, improve the fitting accuracy, and reduce the error.
[0070] It can be understood that step S100 is performed when the system optical path is coaxial.
[0071] Step S200: obtaining the first product dot matrix spot diagram and the second product dot matrix spot diagram of the light beam wavefront phase testing device; the first product dot matrix spot diagram represents the light emitted by the first light source 101, and the spot image obtained by the test camera 500 after the light passes through the first dot matrix card 201, the spectroscopic element 300, the product to be tested 401 and the imaging module 600 to reach the test camera 500; the second product dot matrix spot diagram represents the light emitted by the second light source 102, and the spot image obtained by the test camera 500 after the light passes through the second dot matrix card 202, the spectroscopic element 300, the product to be tested 401 and the imaging module 600 to reach the test camera 500; the first product dot matrix spot diagram and the second product dot matrix spot diagram can obtain the coordinate position of each light spot after the product to be tested is placed, and can calculate the gradient information of multiple light spots in combination with the first system spot diagram and the second system spot diagram obtained in the previous step S100, so as to provide more data for the subsequent step S400 to use the least squares method to fit the wavefront phase, improve the fitting accuracy and reduce the error.
[0072] It can be understood that step S200 is performed when the system optical path is coaxial.
[0073] Step S300: Calculate gradient information based on the first system spot diagram, the second system spot diagram, the first product dotted spot diagram, and the second product dotted spot diagram, where g(x) is the gradient information in the x direction and g(y) is the gradient information in the y direction. The calculation formula for the gradient information represented by g(x) and g(y) is:
[0074]
[0075]
[0076] x is the displacement of the light spot in the x direction, which is equal to the x coordinate of the product light spot position minus the x coordinate of the system light spot position;
[0077] y is the displacement of the light spot in the y direction, which is equal to the y coordinate of the product light spot position minus the y coordinate of the system light spot position;
[0078] a is the focal length of the objective lens. After the control system 800 controls the fourth electric adjustment device 704 to move, it will adjust the focal length of the objective lens of the imaging mold 600, thereby ensuring the imaging quality and improving the test accuracy. Compared with the uncertainty of the characteristics and dimensions of the product 401 to be tested, the data of the objective lens focal length is easy to obtain and more accurate. Using the objective lens focal length as the variable value of the function can simplify the calculation model, making the calculation of the gradient information more intuitive and easy to understand, which helps to reduce errors and uncertainties in the fitting process.
[0079] Step S400: using a fitting method to convert the gradient information into a wavefront phase.
[0080] The control system 800 converts the gradient information into the wavefront phase by the least squares fitting method. The calculation formula of the least squares method is:
[0081] W(x,y)=∫g(x)dx+∫g(y)dy
[0082] W(x,y) is the phase distribution of the entire wavefront, g(x) is the gradient information in the x direction, and g(y) is the gradient information in the y direction.
[0083] Further, in some embodiments of the present invention, the step S100 of acquiring the first system spot diagram and the second system spot diagram of the light beam wavefront phase testing device includes:
[0084] The product carrier 402 and the product to be tested 401 are removed so that they are not in the optical path, ensuring that no external factors interfere with the optical path, thereby obtaining an accurate system spot diagram and ensuring the accuracy of the test.
[0085] The control system 800 lights up the first light source 101, so that the light emitted by the first light source 101 is converted into a first parallel dot matrix light beam through the first dot matrix card 201;
[0086] The first parallel dot matrix light beam passes through the imaging module 600 and the test camera 500 in sequence, and the test camera 500 obtains the first system spot diagram. The imaging module 600 can receive the light and focus it, while maintaining the light path so that the light can reach the test camera 500 smoothly, thereby improving the acquisition accuracy of the first system spot diagram;
[0087] The control system 800 controls the fourth electric adjustment device 704 to move forward and backward, so that the test camera 500 obtains a plurality of first system spot patterns corresponding to different positions;
[0088] The control system 800 turns off the first light source 101 and turns on the second light source 102, so that the light emitted by the second light source 102 is converted into a second parallel dot matrix light beam through the second dot matrix card 202;
[0089] The second parallel dot matrix light beam passes through the beam splitter 300, is refracted by the beam splitter 300, and then passes through the imaging module 600 to reach the test camera 500. The test camera 500 obtains the second system spot pattern. The imaging module 600 can receive the light and focus it, while maintaining the light path so that the light can smoothly reach the test camera 500, thereby improving the acquisition accuracy of the first system spot pattern.
[0090] The control system 800 controls the fourth electric adjustment device 704 to move forward and backward, so that the test camera 500 acquires the second system spot diagrams at multiple different positions.
[0091] The first system spot diagram and the second system spot diagram can obtain the coordinate position of each light spot before the product to be tested is placed, and can be combined with the first product dot matrix spot diagram and the second product dot matrix spot diagram of the next step S200 to calculate the gradient information of multiple light spots, so as to provide more data for the subsequent step S400 to use the least squares method to fit the wavefront phase, improve the fitting accuracy and reduce errors.
[0092] Further, in some embodiments of the present invention, step S200 of obtaining a first product dot matrix spot diagram and a second product dot matrix spot diagram of a light beam wavefront phase testing device includes:
[0093] Put the product 401 to be tested on the product carrier 402, and the control system 800 controls the third electric adjustment device 703 to move the product carrier 402 to the test position and light up the first light source 101;
[0094] The light emitted by the first light source 101 is converted into a first parallel dot matrix light beam through the first dot matrix card 201;
[0095] After the first parallel dot matrix light beam is transmitted through the light splitting element 300, it passes through the product to be tested 401 and the imaging module 600 in sequence and reaches the test camera 500, so that the test camera 500 obtains the first product dot matrix light spot diagram. The imaging module 600 can receive the light and focus it, while maintaining the light path so that the light can smoothly reach the test camera 500, thereby improving the acquisition accuracy of the first light spot diagram of the system;
[0096] The control system 800 controls the fourth electric adjustment device 704 to drive the imaging module 600 and the test camera 500 to move forward and backward, so that the test camera 500 acquires a plurality of first product dot matrix spot images;
[0097] The control system 800 turns off the first light source 101 and turns on the second light source 102;
[0098] The light emitted by the second light source 102 is converted into a second parallel dot matrix light beam through the second dot matrix card 202;
[0099] The second parallel dot matrix light beam passes through the beam splitter 300, is refracted by the beam splitter 300, and then passes through the product to be tested 401 and the imaging module 600 in sequence to reach the test camera 500, so that the test camera 500 obtains the second product dot matrix light pattern. The imaging module 600 can receive the light and focus it, while maintaining the light path so that the light can smoothly reach the test camera 500, thereby improving the acquisition accuracy of the first light pattern of the system;
[0100] The control system 800 controls the fourth electric adjustment device 704 to move forward and backward, so that the test camera 500 acquires the second product dot matrix spot images at multiple different positions.
[0101] Because step S200 has one more step than step S100, that is, placing the product to be tested 401, the parallel dot matrix light beam will be deflected when passing through the product to be tested 401. Therefore, the coordinates of the light spots of the first product dot matrix light pattern and the second product dot matrix light pattern will be offset relative to the first system light pattern and the second system light pattern, respectively. This change characteristic can be used as the basis for the subsequent calculation of gradient information.
[0102] The first product dot matrix light spot diagram and the second product dot matrix light spot diagram can obtain the coordinate position of each light spot after the product to be tested is placed, and can be combined with the first system light spot diagram and the second system light spot diagram obtained in the previous step S100 to calculate the gradient information of multiple light spots, so as to provide more data for the subsequent step S400 to use the least squares method to fit the wavefront phase, improve the fitting accuracy and reduce the error.
[0103] It is understandable that the first dot pattern card 201 and the second dot pattern card 202 in step S100 and step S200 can be different types of dot pattern cards, such as dot pattern cards with different numbers or patterns. Different dot pattern cards can enrich the types of parallel dot matrix light beams and improve the test accuracy.
[0104] Further, in some embodiments of the present invention, the step S300 of calculating the gradient information includes:
[0105] The test camera 500 transmits a plurality of first system spot patterns, a plurality of second system spot patterns, a plurality of first product dot-matrix spot patterns, and a plurality of second product dot-matrix spot patterns to the control system 800;
[0106] The control system 800 obtains the coordinate offset of the light spot of each first system light spot pattern and the corresponding first product dot light spot pattern to obtain the first gradient information;
[0107] The control system 800 obtains the coordinate offset of the light spot of each second system light spot pattern and the corresponding second product dot matrix light spot pattern to obtain the second gradient information.
[0108] The first gradient information and the second gradient information both provide data for the beam wavefront phase fitting method in the subsequent step S400 .
[0109] It should be noted that, in the present embodiment, the obtained coordinate offset represents the displacement of the light spot in the x-direction and the displacement in the y-direction. For example, the coordinate of a light spot a in the first system light spot diagram is (2, 3). After the product 401 to be tested is placed, the parallel dot matrix light beam will be offset after passing through the product 401 to be tested. At this time, the light spot diagram in which the light spot is offset is called the first product light spot diagram. The coordinate of the corresponding light spot a will also change. Assuming that the coordinate of the light spot a after the change is (1, 2), the displacement of the light spot a in the x-direction is x=1-2=-1, and the displacement in the y-direction is y=2-3=-1.
[0110] According to the light beam wavefront phase testing method of the present invention, the light beam emitted by the light source is converted into a parallel dot matrix light beam through the dot matrix card, and reaches the test camera 500 after passing a certain path. The test camera 500 receives two types of spot patterns, namely, the system spot pattern and the product dot matrix spot pattern. The system spot pattern and the product dot matrix spot pattern can respectively obtain the coordinate positions of each light spot in the spot pattern on the test camera 500 before and after the product to be tested 401 is placed. Because the parallel dot matrix light beam will be offset after passing through the product to be tested 401, and the objective lens will be adjusted to change the focal length of the objective lens after the product to be tested 401 is placed, the control system 800 can calculate the gradient information of each light spot through the coordinate offset of the system spot pattern and the product dot matrix spot pattern and the focal length of the objective lens. The data of the focal length of the objective lens is easy to obtain and more accurate. Using the focal length of the objective lens as the variable value of the function can simplify the calculation model, making the calculation of the gradient information more intuitive and easy to understand, which helps to reduce errors and uncertainties in the light beam wavefront phase fitting process.
[0111] In the description of this specification, the description with reference to the terms "one embodiment", "further embodiments", "some specific embodiments" or "some examples" etc. means that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0112] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.
Claims
1. A light beam wavefront phase testing device, characterized in that: include: A first light source, a first dot matrix card, a spectroscopic element, a product to be tested, an imaging module and a test camera are sequentially arranged and maintained coaxially along the propagation direction of the light path; A product carrier, used to carry the product to be tested; A second light source is disposed on one side of the light splitting element; A second dot matrix card, disposed between the light splitting element and the second light source; A control system, electrically connected to the first light source, the second light source, and the test camera respectively; Among them, the light emitted by the first light source passes through the first dot matrix card, the spectroscopic element, the product to be tested and the imaging module in sequence, and enters the test camera; the light emitted by the second light source passes through the second dot matrix card and reaches the spectroscopic element, and is refracted by the spectroscopic element to the product to be tested, and after passing through the product to be tested and the imaging module, enters the test camera.
2. The light beam wavefront phase testing device according to claim 1, characterized in that: The first dot matrix card and the second dot matrix card are respectively provided with dot holes arranged at equal intervals.
3. The light beam wavefront phase testing device according to claim 1, characterized in that: The imaging module comprises an objective lens and a sleeve tube lens which are fixedly connected.
4. The light beam wavefront phase testing device according to claim 1, characterized in that: The light beam wavefront phase testing device also includes a first electric adjustment device, a second electric adjustment device, a third electric adjustment device and a fourth electric adjustment device. The first electric adjustment device, the second electric adjustment device, the third electric adjustment device and the fourth electric adjustment device are all electrically connected to the control system. The first electric adjustment device is used to adjust the position of the first light source, the second electric adjustment device is used to adjust the position of the second light source, the third electric adjustment device is used to adjust the position of the product carrier, and the fourth electric adjustment device is used to adjust the position of the imaging module and the test camera.
5. The light beam wavefront phase testing device according to claim 1, characterized in that: The first light source and / or the second light source can emit parallel light beams of multiple different colors.
6. A method for testing a light beam wavefront phase, applied to a light beam wavefront phase testing device as claimed in any one of claims 1 to 5, characterized in that: The test method includes: Acquire a first system spot diagram and a second system spot diagram of the light beam wavefront phase testing device; the first system spot diagram represents the light emitted by the first light source, and after passing through the first dot pattern card, the spectroscopic element and the imaging module to reach the testing camera, the spot image obtained by the testing camera; the second system spot diagram represents the light emitted by the second light source, and after passing through the second dot pattern card, the spectroscopic element and the imaging module to reach the testing camera, the spot image obtained by the testing camera; Acquire a first product dot matrix spot diagram and a second product dot matrix spot diagram of the light beam wavefront phase testing device; the first product dot matrix spot diagram represents the light emitted by the first light source, and after passing through the first dot matrix card, the spectroscopic element, the product to be tested and the imaging module to reach the test camera, the spot image obtained by the test camera; the second product dot matrix spot diagram represents the light emitted by the second light source, and after passing through the second dot matrix card, the spectroscopic element, the product to be tested and the imaging module to reach the test camera, the spot image obtained by the test camera; Calculating gradient information according to the first system spot diagram, the second system spot diagram, the first product dot matrix spot diagram, and the second product dot matrix spot diagram; The gradient information is converted into wavefront phase using a fitting method.
7. The method for testing the wavefront phase of a light beam according to claim 6, wherein the step of obtaining the first system spot diagram and the second system spot diagram of the light beam wavefront phase testing device comprises: Removing the product carrier and the product to be tested so that they are not in the optical path; The control system lights up the first light source, so that the light emitted by the first light source is converted into a first parallel dot matrix light beam through the first dot matrix card; The first parallel dot matrix light beam passes through the imaging module and the test camera in sequence, and the test camera obtains a first system spot diagram; The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera obtains a plurality of first system spot patterns corresponding to different positions; The control system turns off the first light source and turns on the second light source, so that the light emitted by the second light source is converted into a second parallel dot matrix light beam through the second dot matrix card; The second parallel dot matrix light beam passes through the beam splitter element, is refracted by the beam splitter element, and then passes through the imaging module to reach the test camera, and the test camera obtains a second system spot diagram; The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera acquires the second system spot diagram at multiple different positions.
8. The method for testing the wavefront phase of a light beam according to claim 7, characterized in that: The step of obtaining the first product dot matrix spot diagram and the second product dot matrix spot diagram of the light beam wavefront phase testing device comprises: Put the product to be tested on the product carrier, and the control system controls the third electric adjustment device to move the product carrier to the test position and light up the first light source; The light emitted by the first light source is converted into a first parallel dot matrix light beam through the first dot matrix card; After being transmitted by the beam splitter, the first parallel dot matrix light beam sequentially passes through the product to be tested and the imaging module to reach the test camera, so that the test camera obtains the dot matrix light spot image of the first product; The control system controls the fourth electric adjustment device to drive the imaging module and the test camera to move forward and backward, so that the test camera acquires a plurality of first product dot matrix spot images; The control system turns off the first light source and turns on the second light source; The light emitted by the second light source is converted into a second parallel dot matrix light beam through a second dot matrix card; The second parallel dot matrix light beam passes through the beam splitter element, is refracted by the beam splitter element, and then sequentially passes through the product to be tested and the imaging module to reach the test camera, so that the test camera obtains the dot matrix light spot image of the second product; The control system controls the fourth electric adjustment device to move forward and backward, so that the test camera obtains the second product dot matrix spot images at multiple different positions.
9. The method for testing the wavefront phase of a light beam according to claim 8, characterized in that: The calculated gradient information includes: The test camera transmits a plurality of the first system spot patterns, a plurality of the second system spot patterns, a plurality of the first product dot matrix spot patterns, and a plurality of the second product dot matrix spot patterns to the control system; The control system acquires the coordinate offset of the light spot of each first system light spot pattern and the corresponding first product dot light spot pattern to obtain first gradient information; The control system acquires the coordinate offset of the light spot of each second system light spot pattern and the corresponding second product dot matrix light spot pattern to obtain second gradient information.
10. The method for testing the wavefront phase of a light beam according to claim 6, characterized in that: The step of converting the gradient information into a wavefront phase using a fitting method comprises: The control system converts the gradient information into a wavefront phase by a least squares fitting method, and the calculation formula of the least squares method is: W(x,y)=∫g(x)dx+∫g(y)dy W(x, y) is the phase distribution of the entire wavefront, g(x) is the gradient information in the x direction, and g(y) is the gradient information in the y direction.