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CN-122016254-A - Wave aberration measuring device and method of finite conjugate objective lens

CN122016254ACN 122016254 ACN122016254 ACN 122016254ACN-122016254-A

Abstract

The invention relates to the technical field of wavefront measurement, and provides a wave aberration measuring device and a wave aberration measuring method of a limited conjugate objective lens, wherein the device comprises a light source; the device comprises a light source, a collimation module, a mask, a focusing lens, a wavefront measuring module and a computer, wherein the light source is used for emitting a light beam, the collimation module is used for collimating the light beam emitted by the light source into a parallel light beam, the mask is arranged at the downstream of the collimation module, at least one small hole with the aperture smaller than 1 micron is arranged on the mask, the focusing lens is used for focusing the parallel light beam and penetrating the small hole on the mask, the wavefront measuring module is connected with the computer, and the computer is used for controlling the wavefront measuring module to collect data, process, store and output the collected data. Compared with the prior art that an interferometer is adopted to measure the wave aberration of the finite conjugate objective lens, the wave aberration measuring device of the finite conjugate objective lens provided by the invention has the advantages that the expensive interferometer is not needed, the cost is lower, the objective lenses with different wavelengths can be measured, and the universality is better.

Inventors

  • HE YI
  • HU ZHIXIONG
  • BAO MINGDI
  • HUANG JIANGJIE
  • Ye Xiadi

Assignees

  • 中国科学院苏州生物医学工程技术研究所

Dates

Publication Date
20260512
Application Date
20260224

Claims (10)

  1. 1. A wave aberration measuring apparatus of a finite conjugate objective lens, comprising: A light source (1); The collimation module (2) is arranged at the downstream of the light source (1) and is used for collimating divergent light beams emitted by the light source (1) into parallel light beams; A mask (5) arranged at the downstream of the collimation module (2), wherein the mask (5) is at least provided with a small hole with the aperture smaller than 1 micron; a focusing lens (4) arranged between the collimation module (2) and the mask (5) for focusing the parallel light beam and passing through the small hole on the mask (5); The wavefront measurement module (7) is arranged at the downstream of the mask (5), the wavefront measurement module (7) comprises a first coupling objective lens (701) and a Hartmann-shack wavefront sensor (702) which are connected, and a parallel light beam emergent surface of the first coupling objective lens (701) is arranged adjacent to an incident surface of the Hartmann-shack wavefront sensor (702), the first coupling objective lens (701) is an infinite conjugate objective lens, and the numerical aperture of the first coupling objective lens (701) is not smaller than the numerical aperture of an objective lens to be measured; The computer (8) is connected with the wavefront measurement module (7) and used for controlling the wavefront measurement module (7) to collect data, and processing, storing and outputting the collected data; When in use, the finite conjugate objective lens (6) to be measured is positioned between the mask (5) and the wavefront measurement module (7), and the front focus of the finite conjugate objective lens (6) to be measured is ensured to coincide with the position of the mask (5), and the back focus of the finite conjugate objective lens (6) to be measured is ensured to coincide with the focus of the wavefront measurement module (7).
  2. 2. The wave aberration measuring apparatus of finite conjugate objective lens according to claim 1, wherein, A plurality of small holes are arranged on the mask (5) in an array manner; When the focusing light spots of the focusing lens (4) pass through small holes at different positions on the mask (5), the wave aberration values of different fields of view of the finite conjugate objective lens (6) to be detected can be obtained.
  3. 3. The wave aberration measuring apparatus of finite conjugate objective lens according to claim 2, wherein, The scanning module (3) is arranged between the collimation module (2) and the focusing lens (4); The scanning module (3) enables the focusing light spots of the focusing lens (4) to pass through small holes at different positions on the mask (5) at different scanning moments.
  4. 4. A wave aberration measuring apparatus of finite conjugate objective lens according to claim 3, wherein, The scanning module (3) is two orthogonal scanning galvanometers or MEMS scanning micro-mirrors.
  5. 5. The wave aberration measuring apparatus of finite conjugate objective lens according to claim 2, wherein, The plurality of small holes arranged in an array on the mask (5) are distributed in a two-dimensional array or in a ring-mounted array; The apertures in different positions correspond to different field positions of the finite conjugate objective (6) to be measured.
  6. 6. The wave aberration measuring apparatus of finite conjugate objective lens according to claim 1, wherein, The device also comprises a first precise displacement table (9) and a second precise displacement table (10); the first precise displacement table (9) is used for accommodating the limited conjugate objective lens (6) to be detected and adjusting the position of the limited conjugate objective lens (6) to be detected; The wavefront measurement module (7) is placed on the second precise displacement table (10), and the second precise displacement table (10) is used for adjusting the position of the wavefront measurement module (7).
  7. 7. The wave aberration measuring apparatus of finite conjugate objective lens according to claim 1, wherein, The wavefront measuring module (7) is a calibrated wavefront measuring module (7).
  8. 8. A method of measuring wave aberration of a finite conjugate objective lens, comprising a finite conjugate objective lens wave aberration measuring apparatus according to any one of claims 1 to 7, the method comprising the steps of: the front focus of the finite conjugate objective lens (6) to be detected is overlapped with the position of the mask (5); the focus of the wave front measuring module (7) is overlapped with the back focus of the limited conjugate objective lens (6) to be measured; Acquiring parallel light beams; focusing the parallel light beams and enabling the focusing light spots to pass through small holes on the mask (5); And acquiring a wave phase difference value of the finite conjugate objective lens (6) to be tested.
  9. 9. The method for measuring wave aberration of finite conjugate objective lens according to claim 8, wherein, The wave-front measuring module (7) is controlled by a computer (8) connected with the wave-front measuring module (7) to collect data, and the collected data is processed, stored and output; And/or, measuring with a wavefront measuring module (7) for which calibration has been completed; the method comprises the following steps of calibrating a wavefront measurement module (7): the focus of the wavefront measuring module (7) is overlapped with the focus of the second coupling objective (11), and the optical axes of the second coupling objective (11) and the wavefront measuring module (7) are ensured to be overlapped; Positioning the clear aperture of the pinhole (13) at the focal position of the second coupling objective (11) and the wavefront measuring module (7); acquiring parallel light beams, enabling the parallel light beams to enter a second coupling objective lens (11) for focusing and then propagating the parallel light beams to a pinhole (13); acquiring a wave phase difference value of a finite conjugate objective lens (6) to be tested; wherein the second coupling objective (11) is identical to the first coupling objective (701).
  10. 10. The method for measuring wave aberration of finite conjugate objective lens according to claim 8, wherein, A mask (5) with a plurality of small holes arranged in an array is adopted; the focusing light spots of the focusing lens (4) pass through small holes at different positions on the mask (5) to obtain wave aberration values of different fields of view of the finite conjugate objective lens (6) to be detected.

Description

Wave aberration measuring device and method of finite conjugate objective lens Technical Field The invention relates to the technical field of wavefront measurement, in particular to a wave aberration measuring device and method of a limited conjugate objective lens. Background A wavefront is essentially a curved surface of points having the same phase as a light wave propagates in space. Ideally, the wavefront of a plane wave is a plane, and the wavefront of a spherical wave is a sphere. In practical optical systems, however, the wavefront is distorted due to processing errors of the optical elements, material non-uniformities, and disturbances in the external environment such as atmospheric turbulence. The distortion is accurately measured and converted into quantifiable data, which can provide basis for subsequent wavefront correction or optical system optimization. For wave aberration detection of a finite conjugate objective lens, the wave aberration detection is essentially measurement of wave front phase, and the existing measurement method comprises an interference method, wherein an interferometer, such as a Sophine interferometer and a Thamann-Green interferometer, is adopted, a reference light path is needed, fringes are formed by interference of a wave front to be detected and the reference wave front, and then high-precision wave front information is obtained by a phase demodulation technology. However, the interferometer has high cost, is only suitable for objective lenses with specific wavelengths in the measuring process, and has poor universality. Disclosure of Invention Therefore, the invention aims to solve the problems that the cost of an interferometer is high, the interferometer is only suitable for an objective lens with specific wavelength in the measuring process and the universality is poor when the wavefront phase measurement is carried out by adopting an interferometry in the prior art, and provides a wave aberration measuring device and a wave aberration measuring method of a limited conjugate objective lens. In order to solve the technical problems, the technical scheme of the invention is as follows: The invention provides a wave aberration measuring device of a limited conjugate objective lens, which comprises a light source, a collimation module, a mask, a focusing lens, a wave front measuring module and a wave front measuring module, wherein the collimation module is arranged at the downstream of the light source and is used for collimating a divergent light beam emitted by the light source into a parallel light beam, the mask is arranged at the downstream of the collimation module, at least one small hole with the aperture smaller than 1 micron is arranged on the mask, the focusing lens is arranged between the collimation module and the mask and is used for focusing the parallel light beam and passing through the small hole on the mask, the wave front measuring module is arranged at the downstream of the mask, the wave front measuring module comprises a first coupling objective lens and a Hartmann-shack wave front sensor which are connected, the parallel light beam emitting surface of the first coupling objective lens is adjacent to the incident surface of the Hartmann-shack wave front sensor, the first coupling objective lens is an infinite conjugate objective lens, the numerical aperture of the first coupling objective lens is not smaller than the numerical aperture of an objective lens to be measured, the computer is connected with the wave front measuring module and is used for controlling the wave front measuring module to conduct data acquisition and processing on the acquired data, and storing and outputting the data to be measured, and the data is coincident with the focal point of the front measuring module and the front measuring module is used for ensuring that the focal point is coincident with the focal point of the front measuring module and the front measuring device is limited and the focal point is located between the front measuring module and the front measuring device is used for measuring the conjugate objective lens. Furthermore, a plurality of small holes are arranged on the mask in an array manner, and when focusing light spots of the focusing lens pass through the small holes at different positions on the mask, wave aberration values of different fields of view of the finite conjugate objective lens to be detected can be obtained. Further, the wave aberration measuring device of the finite conjugate objective lens further comprises a scanning module, wherein the scanning module is arranged between the collimation module and the focusing lens, and the scanning module enables focusing light spots of the focusing lens to pass through small holes at different positions on the mask at different scanning moments. Furthermore, the scanning module is two orthogonal scanning galvanometers or MEMS scanning micro-mirrors. Furthermore, the plurality of small h