Wave aberration measuring device and method of limited conjugate objective lens

Abstract

The invention relates to the technical field of wavefront measurement, and provides a wave aberration measuring device and method of a finite conjugate objective lens. The collimation module is used for collimating divergent light beams emitted by the light source into parallel light beams; the mask is arranged at the downstream of the collimation module; at least one small hole with the aperture smaller than 1 micrometer is formed in the mask; the focusing lens is used for focusing the parallel light beams and enabling the parallel light beams to pass through the small holes in the mask; a wavefront measurement module; and the computer is connected with the wavefront measurement module and is used for controlling the wavefront measurement module to carry out data acquisition and processing, storing and outputting the acquired data. Compared with the prior art in which an interferometer is adopted to measure the wave aberration of the limited conjugate objective lens, the wave aberration measuring device of the limited conjugate objective lens provided by the invention does not need to use an expensive interferometer, is lower in cost, can measure objective lenses with different wavelengths, and is better in universality.

Description

Technical Field

[0001] This invention relates to the field of wavefront measurement technology, and specifically to a wavefront aberration measurement device and method for a finite conjugate objective lens. Background Technology

[0002] A wavefront is essentially a surface formed by points with the same phase as a light wave propagates through space. Ideally, the wavefront of a plane wave is a plane, while the wavefront of a spherical wave is a sphere. However, in practical optical systems, wavefront distortion occurs due to manufacturing errors of optical components, material inhomogeneities, and interference from external environments such as atmospheric turbulence. Accurately measuring this distortion and converting it into quantifiable data can provide a basis for subsequent wavefront correction or optical system optimization.

[0003] Wavefront aberration detection for finite conjugate objectives is essentially a measurement of the wavefront phase. Existing methods include interferometry, which uses interferometers such as the Sofie interferometer and the Thyman-Green interferometer. These methods require a reference optical path and involve interference between the wavefront to be measured and the reference wavefront to form fringes. High-precision wavefront information is then obtained through phase demodulation techniques. However, interferometers are expensive and the measurement process is only applicable to objectives of specific wavelengths, resulting in poor versatility. Summary of the Invention

[0004] Therefore, in order to solve the problems of high cost of interferometers and poor versatility when using interferometric methods for wavefront phase measurement in the prior art, this invention provides a wavefront aberration measurement device and method for finite conjugate lenses.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] On one hand, the present invention provides a wavefront aberration measurement device for a finite conjugate objective lens, comprising: a light source; a collimation module disposed downstream of the light source for collimating a diverging beam emitted from the light source into a parallel beam; a mask disposed downstream of the collimation module; the mask having at least one aperture less than 1 micrometer; a focusing lens disposed between the collimation module and the mask for focusing the parallel beam and allowing it to pass through the aperture on the mask; and a wavefront measurement module disposed downstream of the mask; the wavefront measurement module comprising a first coupling objective lens and a Hartmann-Shack wavefront sensor connected together, wherein the first coupling objective lens... The parallel beam exit surface is adjacent to the incident surface of the Hartmann-Shack wavefront sensor; the first coupling objective is an infinite conjugate objective, and the numerical aperture of the first coupling objective is not less than the numerical aperture of the objective under test; a computer, connected to the wavefront measurement module, is used to control the wavefront measurement module to acquire data, and to process, store, and output the acquired data; in use, the finite conjugate objective under test is located between the mask and the wavefront measurement module, ensuring that the front focal point of the finite conjugate objective under test coincides with the position of the mask and that the rear focal point of the finite conjugate objective under test coincides with the focal point of the wavefront measurement module.

[0007] Furthermore, the mask is arrayed with several small holes; when the focused spot of the focusing lens passes through the small holes at different positions on the mask, wavefront aberration values ​​of different fields of view of the finite conjugate objective lens under test can be obtained.

[0008] Furthermore, the wave aberration measurement device of the finite conjugate objective also includes a scanning module disposed between the collimation module and the focusing lens; the scanning module causes the focused spot of the focusing lens to pass through small holes at different positions on the mask at different scanning times.

[0009] Furthermore, the scanning module is two orthogonal scanning mirrors or a MEMS scanning micromirror.

[0010] Furthermore, the array of small holes on the mask is arranged in a two-dimensional array or in a ring array; the small holes at different positions correspond to different field-of-view positions of the finite conjugate objective lens to be tested.

[0011] Furthermore, the wavefront measurement device for the finite conjugate objective also includes a first precision displacement stage and a second precision displacement stage; the first precision displacement stage is used to hold the finite conjugate objective to be measured and to adjust the position of the finite conjugate objective to be measured; the wavefront measurement module is placed on the second precision displacement stage, and the second precision displacement stage is used to adjust the position of the wavefront measurement module.

[0012] Furthermore, the wavefront measurement module is a calibrated wavefront measurement module.

[0013] On the other hand, the present invention also provides a wavefront aberration measurement method for a finite conjugate objective lens, including the wavefront aberration measurement device for a finite conjugate objective lens as described in any one of the above-mentioned methods. The method includes the following steps: aligning the front focal point of the finite conjugate objective lens under test with the mask position; aligning the focal point of the wavefront measurement module with the rear focal point of the finite conjugate objective lens under test; acquiring a parallel beam; focusing the parallel beam and passing the focused spot through a small hole on the mask; and acquiring the wavefront aberration value of the finite conjugate objective lens under test.

[0014] Furthermore, the wavefront measurement module is controlled by a computer connected to it to acquire data, process, store, and output the acquired data; and / or, a calibrated wavefront measurement module is used for measurement; wherein, the calibration steps for the wavefront measurement module are as follows: aligning the focal point of the wavefront measurement module with the focal point of the second coupling lens, and ensuring that the optical axes of the second coupling lens and the wavefront measurement module are aligned; positioning the aperture of the pinhole at the focal point of the second coupling lens and the wavefront measurement module; acquiring a parallel beam, and focusing the parallel beam through the second coupling lens before it propagates to the pinhole; acquiring the wave phase difference value of the finite conjugate lens to be measured; wherein, the second coupling lens is the same as the first coupling lens.

[0015] Furthermore, a mask with several arrayed small holes is used; the focused spot of the focusing lens passes through the small holes at different positions on the mask to obtain wavefront aberration values ​​of different fields of view of the finite conjugate objective lens under test.

[0016] The technical solution of this invention has the following advantages: The wavefront aberration measurement device for a finite conjugate objective lens provided by this invention includes a light source, a collimation module, a focusing lens, a mask, and a wavefront measurement module arranged sequentially along the optical path. The collimation module collimates the diverging beam emitted from the light source into a parallel beam. The mask has at least one aperture smaller than 1 micrometer. The focusing lens focuses the parallel beam through the aperture on the mask. When the wavefront aberration of the finite conjugate objective lens to be measured needs to be measured, the lens is placed between the mask and the wavefront measurement module, ensuring that the front focal point of the lens coincides with the mask and the rear focal point coincides with the focal point of the wavefront measurement module. A computer can then control the wavefront measurement module to acquire data, process, store, and output the acquired data to obtain the wavefront aberration value of the finite conjugate objective lens. Compared to existing technologies that use interferometers to measure the wavefront aberration of finite conjugate objectives, this method eliminates the need for expensive interferometers, resulting in lower costs and greater versatility as it can measure objectives of different wavelengths. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the wave aberration measurement device for a finite conjugate objective lens in an embodiment of the present invention; Figure 2 This is a schematic diagram of the wavefront measurement module in the wavefront aberration measurement device for a finite conjugate objective lens in an embodiment of the present invention. Figure 3 This is a schematic diagram of the optical path of the wavefront measurement module in the wavefront aberration measurement device of the finite conjugate objective lens in an embodiment of the present invention. Figure 4 This is a schematic diagram of the calibration device used in the wavelet aberration measurement process of the finite conjugate objective lens in an embodiment of the present invention; Figure 5 This is a schematic flowchart of the wave aberration measurement method for finite conjugate objectives in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Light source; 2. Collimation module; 3. Scanning module; 4. Focusing lens; 5. Mask; 6. Finite conjugate objective to be tested; 7. Wavefront measurement module; 701. First coupling objective; 702. Hartmann-Shack wavefront sensor; 8. Computer; 9. First precision displacement stage; 10. Second precision displacement stage; 11. Second coupling objective; 12. Adjustment bracket; 13. Pinhole. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and defined, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figure 1 , Figure 2 as well as Figure 3As shown, this embodiment provides a wavefront aberration measurement device for a finite conjugate lens, comprising: a light source 1, for example, a laser light source 1 or an LED light source 1; a collimation module 2, disposed downstream of the light source 1, for collimating the diverging beam emitted from the light source 1 into a parallel beam, for example, the collimation module 2 can be an achromatic lens, a reflective collimator, or a combination of a lens and a reflector; a mask 5, disposed downstream of the collimation module 2; the mask 5 has at least one aperture with a light-transmitting diameter of less than 1 micrometer; a focusing lens 4, disposed between the collimation module 2 and the mask 5, for focusing the parallel beam and passing it through the aperture on the mask 5, for example, the focusing lens 4 can be a doublet and an achromatic lens, which can focus the beam onto the mask 5; and a wavefront measurement module 7, disposed downstream of the mask 5; the wavefront measurement module 7 includes a first coupling objective 701 and a Hartmann-Shack wavefront sensor 702 connected together, and the first coupling objective 701... The parallel beam exit surface of the first coupling objective 701 is arranged adjacent to the incident surface of the Hartmann-Shack wavefront sensor 702. For example, the first coupling objective 701 and the Hartmann-Shack wavefront sensor 702 can be connected and fixed by threads or other mechanical structures to form a wavefront measurement module 7. The first coupling objective 701 is an infinite conjugate objective, and the numerical aperture of the first coupling objective 701 is not less than the numerical aperture of the objective under test. For example, the numerical aperture of the first coupling objective 701 can be the same as the numerical aperture of the objective under test. The computer 8 is electrically connected to the wavefront measurement module 7 and is used to control the wavefront measurement module 7 to acquire data, process, store and output the acquired data. In use, the finite conjugate objective 6 under test is located between the mask 5 and the wavefront measurement module 7, and the front focal point of the finite conjugate objective 6 under test is coincident with the position of the mask 5 and the rear focal point of the finite conjugate objective 6 under test is coincident with the focal point of the wavefront measurement module 7.

[0025] The wavefront measurement device for a finite conjugate objective lens provided in this embodiment includes a light source 1, a collimation module 2, a focusing lens 4, a mask 5, and a wavefront measurement module 7 arranged sequentially along the optical path. The collimation module 2 collimates the diverging beam emitted from the light source 1 into a parallel beam. The mask 5 has at least one small hole with a diameter less than 1 micrometer. The focusing lens 4 focuses the parallel beam and allows it to pass through the small hole in the mask 5. When it is necessary to measure the wavefront aberration of the finite conjugate objective lens 6 to be measured, simply place the finite conjugate objective lens 6 under test... The finite conjugate objective lens 6 is placed between the mask 5 and the wavefront measurement module 7, ensuring that the front focal point of the lens under test (FCP) 6 coincides with the position of the mask 5 and the rear focal point of the FCP 6 coincides with the focal point of the wavefront measurement module 7. The outgoing light from the FCP 6 is a parallel beam, which enters the wavefront measurement module 7 for beam detection. The computer 8 then controls the wavefront measurement module 7 to acquire data, process, store, and output the acquired data, thereby obtaining the wavefront aberration value of the FCP 6. Compared to the existing technology that uses an interferometer to measure the wavefront aberration of finite conjugate objectives, this method eliminates the need for an expensive interferometer, resulting in lower costs. Furthermore, it can measure objectives of different wavelengths, offering better versatility.

[0026] The mask 5 has a series of small holes arranged in an array. When the focused spot of the focusing lens 4 passes through the small holes at different positions on the mask 5, the wavefront aberration values ​​of the finite conjugate objective lens 6 under test at different fields of view can be obtained. For example, the small holes arranged in the array on the mask 5 can be distributed in a two-dimensional array or in a ring array; for example, the mask 5 can be circular or rectangular; when the small holes on the mask 5 are distributed in a two-dimensional array, they can be arranged in parallel rows or columns; when the small holes on the mask 5 are distributed in a ring array, they can be arranged in concentric circles; for example, when the mask 5 is circular, pin holes can be provided only in half of the mask 5, and the other half of the symmetrical area can be left un-holeed. The small holes at different positions correspond to different fields of view positions of the finite conjugate objective lens 6 under test. With this configuration, the wavefront aberration values ​​of the finite conjugate objective lens 6 under test at different fields of view can be obtained, so as to obtain more accurate and comprehensive measurement data, which can provide a basis for subsequent wavefront correction or optical system optimization.

[0027] The wavefront aberration measurement device for the finite conjugate objective lens also includes a scanning module 3, positioned between the collimation module 2 and the focusing lens 4. For example, the scanning module 3 can be two orthogonal scanning mirrors or a MEMS scanning micromirror. This configuration allows the scanning module 3 to perform a two-dimensional scan of the parallel beam output from the collimation module 2, guiding it into the focusing lens 4. Furthermore, at different scanning times, the focused beam from the focusing lens 4 can pass through small holes at different positions on the mask 5 to obtain wavefront aberration values ​​for different fields of view of the finite conjugate objective lens 6 under test.

[0028] The wavefront aberration measurement device for the finite conjugate objective lens further includes a first precision displacement stage 9 and a second precision displacement stage 10. The first precision displacement stage 9 is used to hold the finite conjugate objective lens 6 to be tested and to adjust the position of the finite conjugate objective lens 6 to be tested. For example, the first precision displacement stage 9 can be a three-dimensional precision displacement stage, which can be used to realize the three-dimensional position adjustment of the finite conjugate objective lens 6 to be tested, ensuring that the focal point of the finite conjugate objective lens 6 to be tested coincides with the position of the mask 5.

[0029] The wavefront measurement module 7 is mounted on the second precision displacement stage 10, which is used to adjust the position of the wavefront measurement module 7. For example, the second precision displacement stage 10 can be a five-dimensional precision displacement stage, which can realize five-dimensional position adjustment of the wavefront measurement module 7 to ensure that the focal point of the wavefront measurement module 7 coincides with the back focal point of the finite conjugate objective lens 6 to be measured.

[0030] The wavefront measurement module 7 can be a calibrated wavefront measurement module 7. For example, the wavefront measurement module 7 can be a wavefront measurement module 7 that has been calibrated using spherical waves or parallel beams.

[0031] like Figure 5 As shown, another embodiment also provides a wavefront aberration measurement method for a finite conjugate objective lens, including the wavefront aberration measurement device for a finite conjugate objective lens as described above. The method includes the following steps: aligning the front focal point of the finite conjugate objective lens 6 to be measured with the position of the mask 5; aligning the focal point of the wavefront measurement module 7 with the rear focal point of the finite conjugate objective lens 6 to be measured; acquiring a parallel beam; focusing the parallel beam and passing the focused spot through a small hole on the mask 5; and acquiring the wavefront aberration value of the finite conjugate objective lens 6 to be measured.

[0032] Specifically, the wavefront measurement module 7 is controlled by a computer 8 connected to the wavefront measurement module 7 to acquire data, process, store, and output the acquired data; and / or, a calibrated wavefront measurement module 7 is used for measurement.

[0033] like Figure 4As shown, the calibration device used for calibrating the wavefront measurement module 7 includes a light source 1, a collimation module 2, a second coupling objective lens 11, a pinhole 13, a computer 8, an adjustment bracket 12, a first precision displacement stage 9, and a second precision displacement stage 10. The light source 1, collimation module 2, computer 8, first precision displacement stage 9, and second precision displacement stage 10 can be shared with the light source 1, collimation module 2, computer 8, first precision displacement stage 9, and second precision displacement stage 10 in the measurement device. In the calibration device, the collimation module 2 is located downstream of the light source 1. The beam emitted from the light source 1 is collimated by the collimation module 2 and outputs a parallel beam. The second coupling objective 11 is located downstream of the collimation module 2. For example, the second coupling objective 11 can be the same as the first coupling objective 701, both being infinite conjugate objectives of the same model. The second coupling objective 11 is fixed on the adjustment bracket 12, which can adjust the three-dimensional position of the second coupling objective 11 to ensure that the parallel beam emitted from the collimation module 2 enters the second coupling objective 11. The pinhole 13 is located downstream of the second coupling objective 11 and at the focal point of the second coupling objective 11. The parallel beam is focused by the second coupling objective 11 and propagates to the pinhole 13. The aperture of the pinhole 13 is less than 1 micrometer, which can filter the beam focused by the second coupling objective 11 and improve the quality of the beam. The pinhole 13 can be mounted on the first precision displacement stage 9 to achieve three-dimensional position adjustment of the pinhole 13, ensuring that the light-transmitting aperture of the pinhole 13 is located at the focal point of the second coupling lens 11. The wavefront measurement module 7 is located downstream of the pinhole 13, and the focal point of the wavefront measurement module 7 coincides with the focal point of the second coupling lens 11 at the light-transmitting position of the pinhole 13. The filtered outgoing beam from the pinhole 13 enters the wavefront measurement module 7 for beam detection. The wavefront measurement module 7 can be mounted on the second precision displacement stage 10 to achieve five-dimensional position adjustment of the wavefront measurement module 7, ensuring that the focal point of the wavefront measurement module 7 coincides with the focal point of the second coupling lens 11 at the light-transmitting position of the pinhole 13. The wavefront measurement module 7 can be connected to a computer 8 via a data cable. The computer 8 controls the data acquisition of the wavefront measurement module 7 and performs operations such as processing, storing, and outputting the acquired data.

[0034] The calibration steps for the wavefront measurement module 7 are as follows: The focal point of the wavefront measurement module 7 is aligned with the focal point of the second coupling lens 11, and the optical axes of the second coupling lens 11 and the wavefront measurement module 7 are aligned; the aperture of the pinhole 13 is positioned at the focal point of the second coupling lens 11 and the wavefront measurement module 7; a parallel beam is acquired, and the parallel beam is focused by the second coupling lens 11 and then propagates to the pinhole 13; the phase difference value of the finite conjugate lens 6 to be measured is acquired.

[0035] Specifically, the calibration steps for wavefront measurement module 7 are as follows: Step S11: Turn on light source 1; Step S12: Adjust the adjustment bracket 12 and the second precision displacement stage 10 so that the focal point of the second coupling objective 11 coincides with the focal point of the wavefront measurement module 7, and ensure that the optical axes of the second coupling objective 11 and the wavefront measurement module 7 coincide. Step S13: Adjust the first precision displacement stage 9 to move the pinhole 13 into the optical path so that the light-transmitting aperture of the pinhole 13 is located at the focal position of the second coupling objective lens 11 and the wavefront measurement module 7. Step S14: Under the control of computer 8, wavefront measurement module 7 completes the measurement and records the obtained wavefront aberration, denoted as w0. The wavefront aberration w0 is the self-aberration of the first coupling objective lens 701 in wavefront measurement module 7.

[0036] Step S15: Using the wavefront aberration w0 recorded by computer 8 in step S14 as the reference for wavefront measurement module 7, the calibration of wavefront measurement module 7 is completed.

[0037] In this process, a mask 5 with several arrayed small holes is used; the focused spot of the focusing lens 4 passes through the small holes at different positions on the mask 5 to obtain the wavefront aberration values ​​of different fields of view of the finite conjugate objective lens 6 to be tested.

[0038] The measurement method in this application will now be described through specific embodiments: Step S21: Turn on light source 1; Step S22: The scanning module 3 scans the parallel beam emitted from the collimation module 2, so that the focusing lens 4 focuses the light spot through a small hole i on the mask 5; Step S23: Under the control of computer 8, wavefront measurement module 7 completes a measurement and records the obtained wavefront aberration, denoted as w. i The wavefront aberration w i The wavefront aberration of the finite conjugate objective lens 6 under test in the i-field of view; Repeat steps S22 and S23, changing the scanning position of scanning module 3, and sequentially record the wavefront aberration of the finite conjugate objective lens 6 under different fields of view {j, p, q…}, denoted as {w j w p w q …} represents the wavefront difference value of the objective lens under test in different fields of view.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to cover all possible implementations. Those skilled in the art will recognize that various variations and modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations and modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wavelet aberration measurement device for a finite conjugate objective lens, characterized in that, include: Light source (1); Collimation module (2), located downstream of the light source (1), is used to collimate the divergent beam emitted from the light source (1) into a parallel beam; A mask (5) is disposed downstream of the collimation module (2); the mask (5) has at least one small hole with a diameter of less than 1 micrometer. A focusing lens (4) is disposed between the collimation module (2) and the mask (5) for focusing a parallel beam of light and passing it through the small hole on the mask (5); A wavefront measurement module (7) is disposed downstream of the mask (5); the wavefront measurement module (7) includes a first coupling objective (701) and a Hartmann-Shack wavefront sensor (702) connected together, and the parallel beam exit surface of the first coupling objective (701) is adjacent to the incident surface of the Hartmann-Shack wavefront sensor (702); the first coupling objective (701) is an infinite conjugate objective, and the numerical aperture of the first coupling objective (701) is not less than the numerical aperture of the objective under test; A computer (8) is connected to the wavefront measurement module (7) and is used to control the wavefront measurement module (7) to acquire data, process, store and output the acquired data; In use, the finite conjugate objective (6) to be tested is located between the mask (5) and the wavefront measurement module (7), and the front focal point of the finite conjugate objective (6) to be tested coincides with the position of the mask (5) and the back focal point of the finite conjugate objective (6) to be tested coincides with the focal point of the wavefront measurement module (7).

2. The wavefront aberration measuring device for a finite conjugate objective lens according to claim 1, characterized in that, The mask (5) is provided with a plurality of small holes in an array; When the focused spot of the focusing lens (4) passes through small holes at different positions on the mask (5), the wavefront aberration values ​​of different fields of view of the finite conjugate objective lens (6) to be tested can be obtained.

3. The wavefront aberration measurement device for a finite conjugate objective lens according to claim 2, characterized in that, It also includes a scanning module (3), which is disposed between the collimation module (2) and the focusing lens (4); The scanning module (3) causes the focused spot of the focusing lens (4) to pass through the small holes at different positions on the mask (5) at different scanning times.

4. The wavefront aberration measurement device for a finite conjugate objective lens according to claim 3, characterized in that, The scanning module (3) consists of two orthogonal scanning mirrors or a MEMS scanning micromirror.

5. The wavefront aberration measuring device for a finite conjugate objective lens according to claim 2, characterized in that, The mask (5) has a plurality of small holes arranged in a two-dimensional array or in a ring array. The pinholes at different positions correspond to different field-of-view positions of the finite conjugate objective (6) to be tested.

6. The wavefront aberration measuring device for a finite conjugate objective lens according to claim 1, characterized in that, It also includes a first precision displacement stage (9) and a second precision displacement stage (10); The first precision displacement stage (9) is used to hold the finite conjugate objective (6) to be tested and to adjust the position of the finite conjugate objective (6) to be tested; The wavefront measurement module (7) is placed on the second precision displacement stage (10), which is used to adjust the position of the wavefront measurement module (7).

7. The wavefront aberration measuring device for a finite conjugate objective lens according to claim 1, characterized in that, The wavefront measurement module (7) is a wavefront measurement module (7) that has completed calibration.

8. A method for measuring wavelet aberration of a finite conjugate objective lens, characterized in that, The wavefront aberration measurement device comprising a finite conjugate objective lens as described in any one of claims 1-7, the method comprising the following steps: Make the front focal point of the finite conjugate objective lens (6) to be tested coincide with the position of the mask (5); Make the focal point of the wavefront measurement module (7) coincide with the back focal point of the finite conjugate objective lens (6) to be measured; Obtain a parallel beam; The parallel beam is focused and the focused spot is made to pass through the small hole on the mask (5); Obtain the wave phase difference value of the finite conjugate objective (6) to be tested.

9. The wavelet aberration measurement method for a finite conjugate objective lens according to claim 8, characterized in that, The wavefront measurement module (7) is controlled by a computer (8) connected to the wavefront measurement module (7) to acquire data, process, store and output the acquired data; And / or, use a calibrated wavefront measurement module (7) for measurement; The calibration steps for the wavefront measurement module (7) are as follows: Make the focal point of the wavefront measurement module (7) coincide with the focal point of the second coupling lens (11), and ensure that the optical axes of the second coupling lens (11) and the wavefront measurement module (7) coincide; The aperture of the pinhole (13) is positioned at the focal point of the second coupling objective (11) and the wavefront measurement module (7); Obtain a parallel beam and focus it into the second coupling lens (11) before propagating it to the pinhole (13). Obtain the wave phase difference value of the finite conjugate objective (6) to be tested; The second coupling objective (11) is the same as the first coupling objective (701).

10. The wavelet aberration measurement method for a finite conjugate objective lens according to claim 8, characterized in that, A mask with several arrayed small holes is used (5); The focused spot of the focusing lens (4) is made to pass through small holes at different positions on the mask (5) to obtain wavefront aberration values ​​of different fields of view of the finite conjugate objective lens (6) to be tested.

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