Apparatus and method for calibrating aperture stop area

Abstract

The application relates to a kind of aperture diaphragm area calibration device and calibration test method.The aperture diaphragm area calibration device includes laser, polaroid, focusing lens, pinhole diaphragm, collimating lens and standard detector arranged on the same optical path, and data collector connected with the standard detector, and the aperture diaphragm to be measured is placed on the optical path between collimating lens and standard detector;Standard detector is used to generate corresponding electrical signal according to received optical signal;Data collector is used to receive electrical signal, and determine the calibration test result of the aperture diaphragm to be measured according to the electrical signal.When the area calibration of multiple aperture diaphragms to be measured is needed, only one aperture diaphragm to be measured needs to be placed in the optical path between collimating lens and standard detector in sequence, and the calibration test result corresponding to the aperture diaphragm to be measured can be obtained according to the electrical signal corresponding to the aperture diaphragm to be measured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aperture diaphragm area calibration, in particular to an aperture diaphragm area calibration device and a calibration test method. BACKGROUND

[0002] In the field of radiation remote sensing measurement, the size and position of the aperture diaphragm not only limit the radiation flux of the irradiance instrument, but also determine the solid angle of the radiance instrument; the high-precision aperture diaphragm area measurement precision is a key factor of the calibration precision of the remote sensing radiation instrument.

[0003] At present, the traditional aperture diaphragm area calibration method needs to build two sets of measurement devices to realize the large dynamic calibration of the aperture area from small caliber to large caliber, which is complex and cumbersome to operate. SUMMARY

[0004] Therefore, it is necessary to provide an aperture diaphragm area calibration device and a calibration test method which can be operated simply in view of the above technical problems.

[0005] In a first aspect, the present application provides an aperture diaphragm area calibration device, which comprises:

[0006] a laser, the laser being configured to provide a single-mode parallel Gaussian laser beam;

[0007] a polarizer, the polarizer being configured to receive a vertically polarized light beam which is vertically incident; wherein the vertically polarized light beam is light whose vibration direction is perpendicular to the propagation direction in the single-mode parallel Gaussian laser beam;

[0008] a focusing lens, the focusing lens being disposed on a transmission light path of the polarizer, and being configured to receive the vertically polarized light beam transmitted by the polarizer;

[0009] a pinhole diaphragm, the pinhole diaphragm being disposed on a transmission light path of the focusing lens, and being located at a focal length of the focusing lens, and the pinhole diaphragm being configured to cause a circular aperture diffraction effect of the vertically polarized light beam;

[0010] a collimating lens, the collimating lens being disposed on a transmission light path of the pinhole diaphragm;

[0011] a standard detector, the standard detector being disposed on a transmission light path of the collimating lens, and being configured to generate an electrical signal corresponding to a received light signal; wherein the aperture diaphragm to be measured is placed on a light path between the collimating lens and the standard detector;

[0012] a data collector, the data collector being connected to the standard detector, and being configured to receive the electrical signal, and determine a calibration test result of the aperture diaphragm to be measured according to the electrical signal.

[0013] In one of the embodiments, the scaling device of the aperture area further comprises:

[0014] a condensing system, the condensing system is arranged on the light path between the aperture to be measured and the standard detector;

[0015] a transition aperture, the transition aperture is arranged on the light path between the collimating lens and the standard detector, and the transition aperture is needed to be scaled in area.

[0016] In one of the embodiments, the scaling device of the aperture area further comprises:

[0017] a beam splitter, the beam splitter is arranged on the light path between the polarizer and the focusing lens, and the beam splitter is used to divide the incident light beam into a first sub-beam and a second sub-beam, and the first sub-beam is transmitted to the focusing lens;

[0018] a monitor, the monitor is arranged on the light path of the second sub-beam, and the monitor is used to determine the stability of the vertically polarized light beam according to the received second sub-beam.

[0019] In one of the embodiments, the scaling device of the aperture area further comprises:

[0020] a laser power controller, the laser power controller is arranged on the light path between the polarizer and the focusing lens, and the laser power controller is used to stabilize the power of the vertically polarized light beam.

[0021] In one of the embodiments, the scaling device of the aperture area further comprises:

[0022] at least one mirror, the at least one mirror is used to vertically propagate the single-mode parallel Gaussian laser beam transmitted by the laser to the light entrance side of the polarizer.

[0023] In a second aspect, the present application further provides a scaling test method of aperture area, the method is applied to the scaling device of aperture area described above, and the method comprises:

[0024] arranging the polarizer on the light propagation path of the single-mode parallel Gaussian laser beam transmitted by the laser;

[0025] arranging the focusing lens on the transmission light path of the polarizer;

[0026] arranging the pinhole aperture on the transmission light path of the focusing lens and at the focal length of the focusing lens;

[0027] The collimating lens is arranged on the transmission light path of the pinhole diaphragm, and the distance between the collimating lens and the pinhole diaphragm is equal to the focal length of the collimating lens.

[0028] The standard detector is arranged on the transmission light path of the collimating lens.

[0029] The to-be-tested aperture diaphragm is placed on the light path between the collimating lens and the standard detector, so as to determine the calibration test result of the to-be-tested aperture diaphragm based on the electrical signal received by the data collector.

[0030] In one of the embodiments, when the to-be-tested aperture diaphragm is one, the calibration test result includes the absolute aperture area of the to-be-tested aperture diaphragm; after the step of arranging the standard detector on the transmission light path of the collimating lens, and before the step of placing the to-be-tested aperture diaphragm on the light path between the collimating lens and the standard detector, the calibration test method of the aperture diaphragm area further includes:

[0031] The standard detector is electrically connected with the data collector.

[0032] The small-aperture to-be-tested diaphragm is placed on the light inlet of the standard detector, so that the data collector receives the standard electrical signal based on the uniform parallel light beam from the standard detector.

[0033] The absolute aperture area of the to-be-tested aperture diaphragm is determined based on the electrical signal received by the data collector and the standard electrical signal.

[0034] In one of the embodiments, when the to-be-tested aperture diaphragm is multiple, the calibration test result includes the relative area ratio of the multiple to-be-tested aperture diaphragms, and the calibration test method of the aperture diaphragm area further includes:

[0035] The relative area ratio of the multiple to-be-tested aperture diaphragms is determined based on the ratio of the electrical signals corresponding to the multiple to-be-tested aperture diaphragms received by the data collector.

[0036] In one of the embodiments, when the areas of the multiple to-be-tested aperture diaphragms are all greater than the aperture of the standard detector, before the step of placing the to-be-tested aperture diaphragm on the light path between the collimating lens and the standard detector based on the electrical signal received by the data collector, the calibration test method of the aperture diaphragm area further includes:

[0037] A beam-reducing system is prepared.

[0038] The beam-reducing system is arranged on the light path between the collimating lens and the standard detector.

[0039] In one of the embodiments, when the areas of some of the to-be-tested aperture diaphragms are greater than the aperture of the standard detector, the calibration test method of the aperture diaphragm area further includes:

[0040] Prepare the transition aperture stop;

[0041] The transition aperture stop is placed in the optical path between the collimating lens and the standard detector to obtain the first transition electrical signal corresponding to the transition aperture stop;

[0042] Prepare the beam-contraction system;

[0043] The beam-shrinking system is set in the optical path between the transition aperture stop and the standard detector to obtain the second transition electrical signal corresponding to the transition aperture stop;

[0044] The transition aperture stop is removed from the optical path between the collimating lens and the standard detector, and the large aperture stop under test is placed in the optical path between the collimating lens and the beam shrinking system to obtain the electrical signal corresponding to the large aperture stop under test; wherein, the large aperture stop under test is the aperture stop under test among multiple aperture stops under test whose area is larger than the aperture of the standard detector.

[0045] Based on the electrical signals corresponding to the small aperture test aperture, the first transition electrical signal, the second transition electrical signal, and the electrical signals corresponding to the large aperture test aperture, the relative area ratio of multiple test aperture apertures is determined; wherein, the small aperture test aperture is the test aperture aperture among multiple test aperture apertures whose area is less than or equal to the aperture of the standard detector.

[0046] The aforementioned calibration device and calibration test method for aperture stop area, wherein the calibration device includes a laser, polarizer, focusing lens, pinhole aperture, collimating lens, and standard detector arranged on the same optical path, and a data acquisition unit connected to the standard detector. The aperture stop under test is placed on the optical path between the collimating lens and the standard detector. The standard detector generates a corresponding electrical signal based on the received optical signal. The data acquisition unit receives the electrical signal and determines the calibration test result of the aperture stop under test based on the electrical signal. When multiple aperture stops under test need to be calibrated, only one aperture stop under test needs to be placed sequentially on the optical path between the collimating lens and the standard detector, and the calibration test result corresponding to that aperture stop can be obtained based on the electrical signal corresponding to that aperture stop. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is one of the structural block diagrams of a calibration device for the aperture stop area in one embodiment;

[0049] Figure 2 Structure diagram of a scaling device for aperture area in an embodiment, part 2

[0050] Figure 3 Structure diagram of a scaling device for aperture area in an embodiment, part 3

[0051] Figure 4 Flowchart of a scaling test method for aperture area in an embodiment. DETAILED DESCRIPTION

[0052] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0053] It should be noted that the terms "first", "second", etc. used in the present application can be used to describe various elements or signals, but these elements are not limited by these terms. These terms are only used to distinguish the first element or signal from the second element or signal. The terms "include" and "have" used in the present application and any variations thereof are intended to cover non-exclusive inclusion. The term "multiple" used in the present application refers to two and more than two. The term "and / or" used in the present application refers to one of the options or any combination of multiple options.

[0054] In an exemplary embodiment, as shown in Figure 1 a scaling device 10 for aperture area is provided, comprising a laser 102, a polarizer 104, a focusing lens 106, a pinhole aperture 108, a collimating lens 110, a standard detector 112 and a data collector 114.

[0055] The laser 102 is configured to provide a single-mode parallel Gaussian laser beam.

[0056] The wavelength of the laser 102 needs to be strictly matched with the sensitive wavelength range of the standard detector 112. A silicon-based detector covering a wavelength range of 320-1100 nm is the most commonly used type of standard detector 112. In the case of a silicon-based standard detector 112, a laser 102 with a wavelength of 532 nm can be selected to achieve wavelength matching.

[0057] A laser 102 with high-order mode (such as TEM 10 (Transverse Electromagnetic Mode 10, TEM10) output mode will result in uneven light intensity distribution and increase the edge detection error. A laser 102 with TEM 00The light intensity distribution of the Gaussian beam laser 102 (Transverse Electromagnetic Mode 00, TEM 00) is symmetrical and steep at the edge, which facilitates the precise fitting of the aperture diaphragm, thereby improving the accuracy of the aperture diaphragm area calibration. In TEM 10 10 and TEM 00 00, 10 and 00 represent the characteristics of the light field distribution in the cross section.

[0058] The polarizer 104 is used to receive a vertically incident vertically polarized light beam; wherein the vertically polarized light beam is the light in the single-mode parallel Gaussian laser beam whose vibration direction is perpendicular to the propagation direction.

[0059] The single-mode parallel Gaussian laser beam includes a parallel polarized light beam whose vibration direction is parallel to the propagation direction of the single-mode parallel Gaussian laser beam, and a vertically polarized light beam whose vibration direction is perpendicular to the propagation direction of the single-mode parallel Gaussian laser beam. The polarizer 104 receives and transmits the vertically polarized light beam, while reflecting the light other than the vertically polarized light beam.

[0060] The polarizer 104 can regulate the polarization state of the vertically polarized light beam, thereby eliminating the polarization-dependent error and ensuring the uniformity of the light intensity distribution and the consistency of the response of the standard detector 112.

[0061] The focusing lens 106 is arranged on the transmission light path of the polarizer 104, and the focusing lens 106 is used to receive the vertically polarized light beam transmitted by the polarizer 104.

[0062] The focusing lens 106 can accurately regulate the propagation characteristics of the received vertically polarized light beam, and converge the vertically polarized light beam to the back focal length thereof.

[0063] The pinhole diaphragm 108 is arranged on the transmission light path of the focusing lens 106 and located at the focal length of the focusing lens 106, and the pinhole diaphragm 108 induces the circular hole diffraction effect of the vertically polarized light beam.

[0064] The pinhole diaphragm 108 is arranged at the back focal length of the focusing lens 106, which can maximize the light received by the focusing lens 106. For example, when the diameter of the selected focusing lens 106 is 25 mm, the effective focal length f 1EFL is 25 mm, and the back focal length f 1BFL is 22.47 mm, the distance L1 between the pinhole diaphragm 108 and the focusing lens 106 can be f 1BFL . Wherein, the distance between the pinhole diaphragm 108 and the focusing lens 106 refers to the distance between the pinhole diaphragm 108 and the side of the focusing lens 106 close to the pinhole diaphragm 108.

[0065] Due to factors such as spherical aberration of the focusing lens 106, surface processing errors, scattering from air impurities, and errors in the manual placement of the pinhole stop 108 during assembly, the radius of the focused spot may be larger than the image-side Gaussian beam waist radius of the focusing lens 106. This results in the pinhole stop 108 not perfectly matching the back focal length of the focusing lens. In this case, the size of the pinhole of the pinhole stop 108 can be designed to maximize the incident light from the focusing lens 106 into the pinhole of the pinhole stop 108. For example, when the image-side Gaussian beam waist radius of the focusing lens 106 is 5300 nm, the diameter of the pinhole stop 108 can be 15 μm.

[0066] A collimating lens 110 is disposed in the transmission light path of the pinhole aperture 108 to homogenize and collimate the outgoing light from the pinhole aperture 108.

[0067] The beam emitted from the focusing lens undergoes circular diffraction after passing through the pinhole aperture 108, forming a bright spot in the center and a ring of alternating light and dark edges; the bright spot in the center is called the Airy disk, and the light intensity distribution of the Airy disk is Gaussian.

[0068] Since the Airy disk obtained by diffraction gradually increases in size with distance, and the Gaussian beam gradually becomes more uniform over a larger area as the beam waist increases, the placement position and specifications of the collimating lens 110 can be determined based on the center diameter of the Airy disk. For example, at a distance of 2500mm from the pinhole stop 108, the center diameter of the Airy disk is 25mm, at which point the effective focal length f can be selected. 2EFL The collimating lens 110 has a diameter of 2500mm, meaning the distance L2 between the pinhole stop 108 and the collimating lens 110 is 2500mm. The distance between the pinhole stop 108 and the collimating lens 110 is the distance between the pinhole stop 108 and the side of the collimating lens 110 closest to the pinhole stop 108. Since the collimating lens 110 has a relatively small diameter and is located at the center of the Airy disk, the beam output through the collimating lens 110 can be approximated as a uniform parallel beam.

[0069] A standard detector 112 is disposed in the transmission optical path of the collimating lens 110. The standard detector 112 is used to generate a corresponding electrical signal based on the received optical signal. The aperture stop 20 to be measured is placed in the optical path between the collimating lens 110 and the standard detector 112.

[0070] The data acquisition unit 114 is connected to the standard detector 112. The data acquisition unit 114 is used to receive electrical signals and determine the calibration test results of the aperture stop under test based on the electrical signals.

[0071] When the area calibration of multiple to-be-tested aperture diaphragms needs to be performed, only one to-be-tested aperture diaphragm needs to be placed in the optical path between the collimating lens 110 and the standard detector 112 in sequence, and the calibration test result corresponding to the to-be-tested aperture diaphragm can be obtained according to the electrical signal corresponding to the to-be-tested aperture diaphragm. For example, when there are three to-be-tested aperture diaphragms, the first to-be-tested aperture diaphragm is placed in the optical path between the collimating lens 110 and the standard detector 112, and the electrical signal corresponding to the first to-be-tested aperture diaphragm can be obtained based on the standard detector 112. The calibration test result of the first to-be-tested aperture diaphragm can be determined based on the electrical signal corresponding to the first to-be-tested aperture diaphragm and the data collector 114. The first to-be-tested aperture diaphragm is removed, and the second to-be-tested aperture diaphragm is placed in the optical path between the collimating lens 110 and the standard detector 112. The calibration test result of the second to-be-tested aperture diaphragm can be determined based on the standard detector 112 and the data collector 114. Then, the second to-be-tested aperture diaphragm placed in the optical path between the collimating lens 110 and the standard detector 112 is removed, and the third to-be-tested aperture diaphragm is placed in the optical path between the collimating lens 110 and the standard detector 112. The calibration test result of the third to-be-tested aperture diaphragm can be determined based on the standard detector 112 and the data collector 114. As can be seen, the area calibration steps of multiple to-be-tested aperture diaphragms based on the aperture diaphragm area calibration device 10 are simple. Compared with the traditional aperture diaphragm area calibration device or system, the aperture diaphragm area calibration device 10 does not need to perform XY two-dimensional translation point array scanning on the laser 102, and the calibration test results of multiple to-be-tested aperture diaphragms can be obtained.

[0072] Further, the aperture diaphragm area calibration device 10 can also be used as a set of laser power adjustable uniform parallel light source measuring instruments, and is suitable for all to-be-tested devices that need uniform parallel light beams, and has a wide application range.

[0073] In an exemplary embodiment, as shown in FIG. 1, the aperture diaphragm area calibration device 10 includes a laser 102, a collimating lens 110, a standard detector 112, a data collector 114, and a to-be-tested aperture diaphragm. Figure 2 As shown in FIG. 1, when the area of the to-be-tested aperture diaphragm is greater than the aperture of the standard detector 112, the aperture diaphragm area calibration device 10 further includes a beam-reducing system 116 and a transition aperture diaphragm.

[0074] The beam-reducing system 116 is arranged in the optical path between the to-be-tested aperture diaphragm and the standard detector 112.

[0075] When the area calibration of the transition aperture diaphragm needs to be performed, the transition aperture diaphragm is arranged in the optical path between the collimating lens and the standard detector.

[0076] The beam cross section of the incident light transmitted by the beam shrinking system 116 can be reduced to obtain the exit light with a beam cross section matching the aperture of the standard detector 112. Preferably, the exit port of the beam shrinking system 116 is close to the entrance port of the standard detector 112, so that the exit light after the beam shrinking system 116 can be maximally incident into the entrance port of the standard detector 112, thereby reducing the calibration error.

[0077] If the areas of the multiple to-be-measured aperture stops differ too much, such as there is a 1000-fold or even higher fold difference in area, the energy detection range of the standard detector 112 can be exceeded. At this time, a transition aperture stop and a beam shrinking system 116 can be introduced, and the energy of the laser 102 can be adjusted to perform area calibration of the multiple to-be-measured aperture stops with too large area difference, so that the calibration test result of the transition aperture stop is used as the transition value of the multiple to-be-measured aperture stops with too large area difference, to realize accurate area calibration.

[0078] Taking two to-be-measured aperture stops as an example, if one of the two to-be-measured aperture stops has an area larger than the aperture of the standard detector 112, which is referred to as a large-aperture to-be-measured stop, and the other has an area smaller than or equal to the aperture of the standard detector 112, which is referred to as a small-aperture to-be-measured stop. First, the small-aperture to-be-measured stop is placed on the light path between the collimating lens 110 and the standard detector 112, and the corresponding electrical signal of the small-aperture to-be-measured stop can be obtained based on the standard detector 112; the calibration test result of the small-aperture to-be-measured stop can be determined based on the data collector 114 according to the corresponding electrical signal of the small-aperture to-be-measured stop; the small-aperture to-be-measured stop is removed, a transition aperture stop is prepared, and the transition aperture stop is placed on the light path between the collimating lens 110 and the standard detector 112. Similarly, the first calibration test result of the transition aperture stop can be determined based on the standard detector 112 and the data collector 114; the beam shrinking system 116 is placed on the light path between the transition aperture stop and the standard detector 112, and the second calibration test result of the transition aperture stop can be determined based on the standard detector 112 and the data collector 114; the transition aperture stop is removed, and the large-aperture to-be-measured stop is placed on the light path between the collimating lens 110 and the beam shrinking system 116. Similarly, the calibration test result of the large-aperture to-be-measured stop can be determined based on the standard detector 112 and the data collector 114.

[0079] If both of the two to-be-tested aperture diaphragms are large-aperture to-be-tested aperture diaphragms, first, the first large-aperture to-be-tested aperture diaphragm is placed on the light path between the collimating lens 110 and the standard detector 112, and then the beam-reducing system 116 is placed on the light path between the first large-aperture to-be-tested aperture diaphragm and the standard detector 112, and the standard detector 112 and the data collector 114 are used to determine the calibration test result of the first large-aperture to-be-tested aperture diaphragm; the first large-aperture to-be-tested aperture diaphragm is removed, the second large-aperture to-be-tested aperture diaphragm is placed on the light path between the collimating lens 110 and the beam-reducing system 116, and the standard detector 112 and the data collector 114 are used to determine the calibration test result of the second large-aperture to-be-tested aperture diaphragm.

[0080] In an embodiment, the wavelength of the single-mode parallel Gaussian laser beam provided by the laser 102 is 532 nm, the output mode of the laser 102 is TEM 00 , the beam waist diameter of the single-mode parallel Gaussian laser beam provided by the laser 102 is 1.2 mm, and the full-angle divergence angle of the laser 102 is 1.2 mrad.

[0081] Since the full-angle divergence angle of the laser 102 is too small, the propagation of the Gaussian beam in the laser 102 can be ignored, and the spot diameter output by the laser 102 can be set as the beam waist diameter, i.e., 1.2 mm. 00 The transmission distance of the Gaussian beam in the free space on the optical platform is about 1200 mm, and the spot diameter before the focusing lens 106 is:

[0082]

[0083] wherein, is the spot radius of the Gaussian beam incident on the surface of the focusing lens 106, and L is the transmission distance of the Gaussian beam in the free space on the optical platform.

[0084] In an embodiment, the diameter of the focusing lens 106 is 25 mm, the effective focal length f 1EFL of the focusing lens 106 is 25 mm, and the back focal length f 1BFL of the focusing lens 106 is 22.47 mm.

[0085] In an embodiment, the diameter of the collimating lens 110 is 25 mm, the effective focal length f 2EFL of the collimating lens 110 is 2500 mm, and the back focal length f 2BFL of the collimating lens 110 is 2490.34 mm.

[0086] According to the focusing transmission rule of the Gaussian beam, since the object distance from the waist position of the Gaussian beam to the focusing lens 106 is much larger than the focal length of the focusing lens 106, i.e., >> , then the waist size of the light spot after the focusing lens 106 is:

[0087]

[0088] wherein, is the image-side Gaussian beam waist radius; is the image distance from the image-side Gaussian beam waist to the focusing lens 106; is the focal length of the focusing lens 106; is the wavelength of the single-mode parallel Gaussian laser beam; is the object distance from the object-side Gaussian beam waist to the focusing lens 106.

[0089] In an exemplary embodiment, as shown in FIG. 1, the aperture stop area scaling device 10 further comprises a standard detector 112. Figure 2 and Figure 3 The standard detector 112 is disposed in the light path of the second split beam.

[0090] The standard detector 112 is used to determine the stability of the vertically polarized light beam according to the received second split beam.

[0091] The standard detector 112 is used to determine the stability of the vertically polarized light beam according to the received second split beam.

[0092] Based on the beam splitter 118 and the monitor 120, the stability of the vertically polarized light beam can be detected. When the data stability obtained by the monitor 120 is below the level of 0.03%, it can be considered that the laser power of the vertically polarized light beam is stable.

[0093] In an embodiment, the splitting ratio of the beam splitter 118 can be 1:9, so that 10% of the vertically polarized light beam is transmitted into the monitor 120, and the remaining 90% of the vertically polarized light beam is transmitted into the focusing lens 106, so as to ensure that the energy entering the focusing lens 106 is within the linear energy response range of the standard detector 112.

[0094] Since the diameter of the small-aperture aperture stop to be measured is small, the energy entering the standard detector 112 is small, and the standard detector 112 has low sensitivity to small energy, and there is a risk that small energy cannot be detected. Therefore, by increasing the vertically polarized light beam transmitted into the focusing lens 106, the energy entering the standard detector 112 can be increased, thereby ensuring the normal operation of the scaling test of the small-aperture aperture stop to be measured.

[0095] In one embodiment, in case that the stability of the vertically polarized light beam obtained by the monitor 120 does not meet the requirement, the laser 102 is turned on in advance for preheating, and the area calibration of the to-be-tested aperture diaphragm is performed after the energy of the laser 102 is stabilized.

[0096] In one exemplary embodiment, as shown in Figure 2 and Figure 3 , the aperture diaphragm area calibration device 10 further comprises a laser power controller 122.

[0097] The laser power controller 122 is arranged on the light path between the polarizer 104 and the focusing lens 106; the laser power controller 122 is used for power stabilization of the vertically polarized light beam, thereby improving the calibration accuracy of the to-be-tested aperture diaphragm.

[0098] In one embodiment, in case that the stability of the vertically polarized light beam obtained by the monitor 120 does not meet the requirement, the laser power controller 122 is turned on in advance for preheating, and the area calibration of the to-be-tested aperture diaphragm is performed after the performance of the laser power controller 122 is stabilized.

[0099] In one exemplary embodiment, as shown in Figure 2 and Figure 3 , in case that the placement position of the laser 102 cannot make the single-mode parallel Gaussian laser beam vertically incident to the polarizer 104, the aperture diaphragm area calibration device 10 further comprises at least one mirror 124.

[0100] The at least one mirror 124 is used for vertically propagating the single-mode parallel Gaussian laser beam transmitted by the laser 102 to the light entrance side of the polarizer 104.

[0101] The volume of the laser 102 is large, and the space of the aperture area calibration device 10 is small, so that the single-mode parallel Gaussian laser beam transmitted by the laser 102 cannot be vertically incident to the polarizer 104. In this case, at least one mirror 124 can be introduced. For example, two mirrors 124 can be introduced to reduce the area occupied by the aperture area calibration device 10 in a certain direction by increasing the optical path. Specifically, the laser 102 is placed on an elevated platform, and the height and angle of the laser 102 are adjusted so that the transmitted light path of the laser 102 is perpendicular to the receiving surface of the polarizer 104, and the center of the transmitted light path of the laser 102 is at the same level as the center of the receiving surface of the polarizer 104. The first mirror 124 is placed on the transmitted light path of the laser 102 and is inclined at 45°, so that the single-mode parallel Gaussian laser beam is turned by 90°. The second mirror 124 is placed on the transmitted light path of the first mirror 124 and is inclined at 45°, so that the single-mode parallel Gaussian laser beam is turned by 90° and is vertically incident to the polarizer 104.

[0102] In one embodiment, as shown in Figure 2 and Figure 3 the aperture area calibration device 10 further comprises an adjustment platform 126.

[0103] The adjustment platform 126 is used to adjust the position of the standard detector 112, so that the light inlet of the standard detector 112 corresponds to the transmitted light path of the collimating lens 110.

[0104] In one exemplary embodiment, as shown in Figure 4 a method for calibrating the aperture area is also provided. The method is applied to the aperture area calibration device described above, and the method comprises the following steps:

[0105] S402, the polarizer is arranged on the light propagation path of the transmitted single-mode parallel Gaussian laser beam of the laser.

[0106] S404, the focusing lens is arranged on the transmitted light path of the polarizer.

[0107] S406, the pinhole diaphragm is arranged on the transmitted light path of the focusing lens and at the focal length of the focusing lens.

[0108] S408, the collimating lens is arranged on the transmitted light path of the pinhole diaphragm, and the distance between the collimating lens and the pinhole diaphragm is equal to the focal length of the collimating lens.

[0109] S410, the standard detector is arranged on the transmitted light path of the collimating lens.

[0110] S412, placing the to-be-tested aperture diaphragm on the light path between the collimating lens and the standard detector to determine the calibration test result of the to-be-tested aperture diaphragm based on the electrical signal received by the data collector.

[0111] After the polarizer focusing lens, the pinhole diaphragm, the collimating lens and the standard detector are set, the to-be-tested aperture diaphragm is placed on the light path between the collimating lens and the standard detector, and the corresponding electrical signal of the to-be-tested aperture diaphragm can be obtained based on the standard detector; the calibration test result of the to-be-tested aperture diaphragm can be determined based on the electrical signal corresponding to the to-be-tested aperture diaphragm received by the data collector; the to-be-tested aperture diaphragm is removed, and the area calibration of the to-be-tested aperture diaphragm is completed. If the area calibration of another to-be-tested aperture diaphragm is needed, the to-be-tested aperture diaphragm is directly placed on the light path between the collimating lens and the standard detector, and the calibration test result of the to-be-tested aperture diaphragm can be determined based on the standard detector and the data collector without assembling another set of aperture diaphragm area calibration device, which is simple to operate.

[0112] In an exemplary embodiment, after the step of placing the polarizer on the light propagation path of the transmitted single-mode parallel Gaussian laser beam of the laser, and before the step of placing the focusing lens on the transmitted light path of the polarizer, the calibration test method of the aperture diaphragm area further comprises:

[0113] The laser power controller is placed on the light path between the polarizer and the focusing lens.

[0114] The laser power of the vertically polarized light beam can be adjusted by the laser power controller to keep it at a constant level, so as to improve the reliability of the aperture diaphragm area calibration result.

[0115] In an exemplary embodiment, when the to-be-tested aperture diaphragm is one, the calibration test result includes the absolute aperture area of the to-be-tested aperture diaphragm; after the step of placing the standard detector on the transmitted light path of the collimating lens, and before the step of placing the to-be-tested aperture diaphragm on the light path between the collimating lens and the standard detector, the calibration test method of the aperture diaphragm area further comprises:

[0116] The standard detector is electrically connected with the data collector.

[0117] The small aperture diaphragm is placed on the light inlet of the standard detector, so that the data collector receives the standard electrical signal based on the uniform parallel light beam from the standard detector.

[0118] The absolute aperture area of the to-be-tested aperture diaphragm is determined based on the electrical signal received by the data collector and the standard electrical signal.

[0119] If it is necessary to determine the absolute aperture area of the to-be-tested aperture diaphragm, the small aperture diaphragm can be placed at the light inlet of the standard detector, so that the light passing through the small aperture diaphragm is a uniform parallel light beam. In this case, the standard detector can obtain a standard electrical signal of the uniform parallel light beam. The output voltage corresponding to the to-be-tested aperture diaphragm is obtained based on the standard detector and the data collector, and thus the absolute aperture area of the to-be-tested aperture diaphragm is obtained.

[0120]

[0121] wherein S1 is the absolute aperture area of the to-be-tested aperture diaphragm, U1 is the output voltage corresponding to the to-be-tested aperture diaphragm, and U3 is the standard electrical signal. The voltage signal output by the standard detector is proportional to the size of the absolute aperture area of the to-be-tested aperture diaphragm.

[0122] In an exemplary embodiment, when the to-be-tested aperture diaphragm is multiple, the calibration test result includes the relative area ratio of the multiple to-be-tested aperture diaphragms, and the calibration test method of the aperture diaphragm area further includes:

[0123] Based on the ratio of the electrical signals corresponding to the multiple to-be-tested aperture diaphragms received by the data collector, the relative area ratio of the multiple to-be-tested aperture diaphragms is determined.

[0124] Taking the case of two to-be-tested aperture diaphragms as an example, if the areas of the two to-be-tested aperture diaphragms are both less than or equal to the aperture of the standard detector, the to-be-tested aperture diaphragms can be placed in the light path between the collimating lens and the standard detector in sequence, and the relative area ratio of the two to-be-tested aperture diaphragms is determined based on the electrical signals received by the data collector. If the areas of the two to-be-tested aperture diaphragms are both greater than the aperture of the standard detector, the to-be-tested aperture diaphragms can be placed in the light path between the collimating lens and the beam-reducing system in sequence in the case of assembling the beam-reducing system, and the relative area ratio of the two to-be-tested aperture diaphragms is determined based on the electrical signals received by the data collector. If the area of one to-be-tested aperture diaphragm is greater than the aperture of the standard detector, and the area of the other to-be-tested aperture diaphragm is less than or equal to the aperture of the standard detector, a transition aperture diaphragm can be introduced, the to-be-tested aperture diaphragm and the transition aperture diaphragm whose areas are less than or equal to the aperture of the standard detector are placed in the light path between the collimating lens and the standard detector in sequence, and then the to-be-tested aperture diaphragm and the transition aperture diaphragm whose areas are greater than the aperture of the standard detector are placed in the light path between the collimating lens and the beam-reducing system in sequence in the case of assembling the beam-reducing system, and the relative area ratio of the two to-be-tested aperture diaphragms is determined based on the electrical signals received by the data collector.

[0125] In the case that the areas of the two to-be-tested aperture diaphragms are both less than or equal to the aperture of the standard detector, the calculation formula for determining the relative area ratio of the two to-be-tested aperture diaphragms is as follows:

[0126]

[0127] Wherein, Ua is the relative area ratio of two aperture stops to be measured, which are both less than or equal to the aperture of the standard detector, E is the illumination received by the aperture stop to be measured per unit area, S is the projection area of the aperture stop to be measured perpendicular to the propagation direction of the laser beam, U1 is the electrical signal corresponding to one of the aperture stops to be measured, U2 is the electrical signal corresponding to the other aperture stop to be measured, D1 is the diameter corresponding to one of the aperture stops to be measured, D2 is the diameter corresponding to the other aperture stop to be measured, S1 is the area corresponding to one of the aperture stops to be measured, and S2 is the area corresponding to the other aperture stop to be measured.

[0128] In an exemplary embodiment, in the case where the areas of the plurality of aperture stops to be measured are all greater than the aperture of the standard detector, before the step of placing the aperture stop to be measured in the optical path between the collimating lens and the standard detector to determine the electrical signal received by the data collector, the method for calibrating the area of the aperture stop further comprises:

[0129] Preparing a beam-reducing system.

[0130] Placing the beam-reducing system in the optical path between the collimating lens and the standard detector.

[0131] Taking two aperture stops to be measured as an example, if the areas of the two aperture stops to be measured are both greater than the aperture of the standard detector, the first aperture stop to be measured is placed in the optical path between the collimating lens and the standard detector, then the beam-reducing system is prepared and placed in the optical path between the first aperture stop to be measured and the standard detector, and the calibration test result of the first aperture stop to be measured is determined based on the standard detector and the data collector; the first aperture stop to be measured is removed, the second aperture stop to be measured is placed in the optical path between the collimating lens and the beam-reducing system, and the calibration test result of the second aperture stop to be measured is also determined based on the standard detector and the data collector.

[0132] In the case where the areas of the two aperture stops to be measured are both greater than the aperture of the standard detector, the calculation formula for determining the relative area ratio of the two aperture stops to be measured is as follows:

[0133]

[0134] Wherein, Ub is the relative area ratio of the two apertures to be measured, E is the luminous intensity received by the aperture to be measured per unit area, S is the projection area of the aperture to be measured perpendicular to the propagation direction of the laser beam, U4 is the electrical signal corresponding to one of the apertures to be measured, U5 is the electrical signal corresponding to the other aperture to be measured, D4 is the diameter corresponding to one of the apertures to be measured, D5 is the diameter corresponding to the other aperture to be measured, S4 is the area corresponding to one of the apertures to be measured, and S5 is the area corresponding to the other aperture to be measured.

[0135] In the case of using a beam-reducing system, the energy of the laser can be adjusted lower, and the laser power of the vertically polarized light beam can also be reduced based on the laser power controller.

[0136] In an exemplary embodiment, in the case where the area of the part of the aperture to be measured is larger than the aperture of the standard detector, the above-mentioned aperture area calibration test method further comprises:

[0137] Prepare a transition aperture.

[0138] Place the transition aperture on the light path between the collimating lens and the standard detector to obtain a first transition electrical signal corresponding to the transition aperture.

[0139] Prepare a beam-reducing system.

[0140] Place the beam-reducing system on the light path between the transition aperture and the standard detector to obtain a second transition electrical signal corresponding to the transition aperture.

[0141] Remove the transition aperture from the light path between the collimating lens and the standard detector, and place the large-aperture aperture to be measured on the light path between the collimating lens and the beam-reducing system to obtain an electrical signal corresponding to the large-aperture aperture to be measured; wherein the large-aperture aperture to be measured is the aperture to be measured in the plurality of apertures to be measured whose area is larger than the aperture of the standard detector.

[0142] Determine the relative area ratio of the plurality of apertures to be measured according to the electrical signal corresponding to the small-aperture aperture to be measured, the first transition electrical signal, the second transition electrical signal, and the electrical signal corresponding to the large-aperture aperture to be measured; wherein the small-aperture aperture to be measured is the aperture to be measured in the plurality of apertures to be measured whose area is smaller than or equal to the aperture of the standard detector.

[0143] Taking two to-be-measured aperture diaphragms as an example, if among the two to-be-measured aperture diaphragms, there is a to-be-measured aperture diaphragm with an area greater than the aperture of the standard detector, which is recorded as a large-aperture to-be-measured diaphragm, and there is a to-be-measured aperture diaphragm with an area less than or equal to the aperture of the standard detector, which is recorded as a small-aperture to-be-measured diaphragm. First, the small-aperture to-be-measured diaphragm is placed on the light path between the collimating lens and the standard detector, and the corresponding electrical signal of the small-aperture to-be-measured diaphragm can be obtained based on the standard detector; the small-aperture to-be-measured diaphragm is removed, a transition aperture diaphragm is prepared, and the transition aperture diaphragm is placed on the light path between the collimating lens and the standard detector, and the first transition signal corresponding to the transition aperture diaphragm is determined based on the standard detector; the beam-reducing system is placed on the light path between the transition aperture diaphragm and the standard detector, and the second transition signal corresponding to the transition aperture diaphragm is determined based on the standard detector; the transition aperture diaphragm is removed, and the large-aperture to-be-measured diaphragm is placed on the light path between the collimating lens and the beam-reducing system, and the electrical signal corresponding to the large-aperture to-be-measured diaphragm is determined based on the standard detector.

[0144] According to the electrical signal corresponding to the small-aperture to-be-measured diaphragm, the first transition electrical signal, the second transition electrical signal, and the electrical signal corresponding to the large-aperture to-be-measured diaphragm, the calculation formula of the relative area ratio of the plurality of to-be-measured aperture diaphragms is as follows:

[0145]

[0146] Wherein, Uc is the relative area ratio between the small-aperture to-be-measured diaphragm and the large-aperture to-be-measured diaphragm, E is the luminous intensity received by the to-be-measured aperture diaphragm per unit area, S is the projection area of the to-be-measured aperture diaphragm perpendicular to the propagation direction of the laser beam, U6 is the electrical signal corresponding to the small-aperture to-be-measured diaphragm, U7 is the electrical signal corresponding to the large-aperture to-be-measured diaphragm, D6 is the diameter corresponding to the small-aperture to-be-measured diaphragm, D7 is the diameter corresponding to the large-aperture to-be-measured diaphragm, S6 is the area corresponding to the small-aperture to-be-measured diaphragm, S7 is the area corresponding to the large-aperture to-be-measured diaphragm, U0 is the first transition electrical signal, U0' is the second transition electrical signal, D0 is the diameter corresponding to the transition aperture diaphragm, S0 is the area corresponding to the transition aperture diaphragm.

[0147] It should be noted that when placing the to-be-measured aperture diaphragm and the transition aperture diaphragm, the to-be-measured aperture diaphragm and the transition aperture diaphragm can be placed close to the light inlet of the standard detector; in the case of using the beam-reducing system, the to-be-measured aperture diaphragm and the transition aperture diaphragm can be placed close to the light inlet of the beam-reducing system, and / or the beam-reducing system can be placed close to the light inlet of the standard detector.

[0148] It should be understood that, although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences. Moreover, at least some of the steps in the flowcharts involved in the above-described embodiments can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least some of the other steps or the steps or stages in the other steps. It can be understood that the steps in different embodiments can be freely combined as needed, and any non-contradictory scheme formed by the combination shall be considered within the scope of the present application.

[0149] The technical features of the above embodiments can be combined in any manner. For brevity, not all possible combinations of the technical features in the above embodiments are described, but any combination of the technical features that does not result in a contradiction shall be considered within the scope of the present application.

[0150] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be considered within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the appended claims.

Claims

1. A calibration device for the area of ​​an aperture stop, characterized in that, The calibration device for the aperture stop area includes: A laser for providing a single-mode parallel Gaussian laser beam; A polarizer is used to receive a vertically incident vertically polarized light beam; wherein the vertically polarized light beam is light whose vibration direction is perpendicular to the propagation direction in the single-mode parallel Gaussian laser beam. A focusing lens is disposed in the transmission light path of the polarizer, and the focusing lens is used to receive the vertically polarized light beam transmitted by the polarizer; A pinhole aperture is disposed in the transmission light path of the focusing lens and located at the focal length of the focusing lens. The pinhole aperture induces a circular aperture diffraction effect in the vertically polarized beam. A collimating lens is disposed in the transmission light path of the pinhole aperture, and the distance between the collimating lens and the pinhole aperture is equal to the focal length of the collimating lens. A standard detector is disposed in the transmission optical path of the collimating lens, and the standard detector is used to generate a corresponding electrical signal based on the received optical signal; wherein, the aperture stop to be measured is placed in the optical path between the collimating lens and the standard detector; A data acquisition unit is connected to the standard detector. The data acquisition unit is used to receive the electrical signal and determine the calibration test result of the aperture stop under test based on the electrical signal. When the area of ​​the aperture stop to be tested is larger than the aperture of the standard detector, the method further includes: A beam-shrinking system is disposed in the optical path between the aperture stop to be measured and the standard detector; A transition aperture stop is provided in the optical path between the collimating lens and the standard detector when area calibration is required.

2. The calibration device for the aperture stop area according to claim 1, characterized in that, Also includes: A beam splitter is disposed in the optical path between the polarizer and the focusing lens. The beam splitter is used to split the incident light beam into a first beam splitter and a second beam splitter, and the first beam splitter is transmitted to the focusing lens. A monitor is disposed in the optical path of the second beam splitter, and the monitor is used to determine the stability of the vertically polarized beam based on the received second beam splitter.

3. The calibration device for the aperture stop area according to claim 1, characterized in that, Also includes: A laser power controller is disposed in the optical path between the polarizer and the focusing lens; the laser power controller is used to stabilize the power of the vertically polarized beam.

4. The calibration device for the aperture stop area according to claim 1, characterized in that, In cases where the laser's placement position prevents the single-mode parallel Gaussian laser beam from being perpendicularly incident on the polarizer, the method further includes: At least one reflector is provided for perpendicularly propagating a single-mode parallel Gaussian laser beam transmitted by the laser to the incident side of the polarizer.

5. A calibration test method for aperture stop area, characterized in that, The method is applied to the calibration device for the aperture stop area as described in any one of claims 1 to 4, and the method includes: The polarizer is placed on the light propagation path of the transmitted single-mode parallel Gaussian laser beam from the laser. A focusing lens is placed in the transmission light path of the polarizer; The pinhole aperture is set in the transmission light path of the focusing lens and is located at the focal length of the focusing lens; A collimating lens is placed in the transmission light path of the pinhole aperture, and the distance between the collimating lens and the pinhole aperture is equal to the focal length of the collimating lens. A standard detector is placed in the transmission light path of the collimating lens; The aperture stop under test is placed in the optical path between the collimating lens and the standard detector, so that the calibration test result of the aperture stop under test can be determined based on the electrical signal received by the data acquisition unit.

6. The method according to claim 5, characterized in that, When there is only one aperture stop under test, the calibration test result includes the absolute aperture area of ​​the aperture stop under test; after the step of setting the standard detector in the transmission optical path of the collimating lens, and before the step of placing the aperture stop under test in the optical path between the collimating lens and the standard detector, the method further includes: Electrically connect the standard detector to the data acquisition unit; A small aperture stop is placed at the entrance of the standard detector so that the data acquisition unit receives a standard electrical signal based on a uniform parallel beam from the standard detector. Based on the electrical signal received by the data acquisition device and the standard electrical signal, the absolute aperture area of ​​the aperture stop under test is determined.

7. The method according to claim 5, characterized in that, When there are multiple aperture stops to be tested, the calibration test results include the relative area ratios of the multiple aperture stops to be tested, and the method further includes: The relative area ratio of the multiple aperture stops under test is determined based on the ratio of the electrical signals corresponding to the multiple aperture stops under test received by the data acquisition device.

8. The method according to claim 7, characterized in that, When the areas of the plurality of aperture stops to be tested are all larger than the aperture of the standard detector, prior to the step of placing the aperture stops to be tested in the optical path between the collimating lens and the standard detector, based on the electrical signal received by the data acquisition unit, the method further includes: Prepare the beam-contraction system; The beam-shrinking system is positioned in the optical path between the collimating lens and the standard detector.

9. The method according to claim 7, characterized in that, When the area of ​​a portion of the aperture stop to be tested is larger than the aperture of the standard detector, the method further includes: Prepare the transition aperture stop; The transition aperture stop is placed in the optical path between the collimating lens and the standard detector to obtain the first transition electrical signal corresponding to the transition aperture stop; Prepare the beam-contraction system; The beam-shrinking system is set in the optical path between the transition aperture stop and the standard detector to obtain the second transition electrical signal corresponding to the transition aperture stop; The transition aperture stop is removed from the optical path between the collimating lens and the standard detector, and the large aperture test stop is placed in the optical path between the collimating lens and the beam shrinking system to obtain the electrical signal corresponding to the large aperture test stop; wherein, the large aperture test stop is the aperture stop with an area larger than the aperture of the standard detector among a plurality of aperture stops to be tested. The relative area ratio of the plurality of aperture diaphragms is determined based on the electrical signal corresponding to the small aperture diaphragm under test, the first transition electrical signal, the second transition electrical signal, and the electrical signal corresponding to the large aperture diaphragm under test; wherein, the small aperture diaphragm under test is the aperture diaphragm under test among the plurality of aperture diaphragms under test whose area is less than or equal to the aperture of the standard detector.

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