CN-121977706-A - Shack-Hartmann wavefront sensor sub-aperture light spot intensity crosstalk suppression device

CN121977706ACN 121977706 ACN121977706 ACN 121977706ACN-121977706-A

Abstract

The invention provides a cross-talk suppression device for sub-aperture light spot intensity of a shack-Hartmann wavefront sensor, and belongs to the technical field of optical wavefront aberration measurement. The device comprises a micro lens array, a light spot intensity crosstalk suppressor, an image sensor and a data processing computer. The micro lens array divides the collimated light beam into multiple paths of sub light beams and focuses the sub light beams, the light spot intensity crosstalk suppressor is arranged between the micro lens array and the image sensor, three-dimensional physical isolation of adjacent sub aperture light spots is realized through a light absorption material or an optical waveguide structure, intensity crosstalk is suppressed, the image sensor collects sub light spot images after isolation, and the data processing computer calculates the mass center position of each sub aperture light spot. The method realizes crosstalk suppression at the hardware level, improves centroid calculation precision, stability and robustness, and is suitable for wavefront detection under the conditions of high dynamic range and complex light field.

Inventors

LI ZHAOCONG
HUANG LINHAI
WU XIAOSONG
ZHANG XI

Assignees

中国科学院光电技术研究所

Dates

Publication Date: 20260505
Application Date: 20260114

Claims (10)

1. The device for suppressing the cross talk of the spot intensity of the sub-aperture of the shack-Hartmann wavefront sensor is characterized by comprising: microlens array with focal length of Receiving the collimated light beam and dividing it into × Sub-beams, wherein Focusing on the effective target surface of the image sensor, wherein the number of sub apertures of the micro lens array is the same as the number of focusing sub beams; The light spot intensity crosstalk suppressor is arranged between the micro lens array and the image sensor and aligned with the sub apertures of the micro lens array one by one, and comprises a physical isolation structure formed by light absorption materials or light waveguide structures, and is used for carrying out three-dimensional physical isolation on light spots of the sub apertures of the adjacent micro lens arrays so as to suppress intensity crosstalk among the sub light spots; The image sensor is positioned at the focal plane of the micro lens array and is used for acquiring the sub-facula image processed by the facula intensity crosstalk suppressor; And the data processing computer is used for calculating the centroid position of the light spot in the sub-aperture of the micro lens array based on the sub-light spot image.
2. The device for suppressing spot intensity crosstalk between sub-apertures of a shack-Hartmann wavefront sensor as set forth in claim 1 wherein the sub-apertures of the microlens array are arranged in a square, circular or hexagonal array, and focal lengths, pitches, sizes and shapes of the sub-apertures of all the microlens array are the same.
3. A sub-aperture spot intensity crosstalk suppression device of a shack-Hartmann wavefront sensor as set forth in claim 1 wherein said spot intensity crosstalk suppressor is divided into × A sub-region of total length of , Is a real number greater than 0, Focal length of microlens array The shape, size and number of the subareas of the spot intensity crosstalk suppressor are the same as those of the subareas of the micro lens array, the boundary adopts a light absorbing material or an optical waveguide structure, and the boundary width is equal to that of the subareas The adjustment is made according to the spot size and dynamic range, Is a real number greater than 0, and Less than half the sub-aperture length of the microlens array.
4. The device for suppressing spot intensity crosstalk of sub-apertures of a shack-Hartmann wavefront sensor as set forth in claim 1 wherein the spot intensity crosstalk suppressor is a micro-structured array comprising a light absorbing material or an optical waveguide structure, and each isolation unit of the micro-structured array is aligned with a sub-aperture of the micro-lens array one by one for three-dimensionally and physically isolating spots of adjacent sub-apertures.
5. The device for suppressing spot intensity crosstalk of sub-apertures of a shack-Hartmann wavefront sensor as set forth in claim 4, wherein said microstructure array is a high aspect ratio grid-like wall structure realized by three-dimensional printing or by Length of is Is composed of a sub-structure laminated layer, wherein Is an integer greater than 0 and is selected from the group consisting of, Is a real number greater than 0, and ≤ 。
6. The device of claim 1, wherein the position or angle of the spot intensity crosstalk suppressor relative to the microlens array or the image sensor is adjustable to accommodate different spot offset ranges and dynamic measurement requirements.
7. The device for suppressing spot intensity crosstalk of a sub-aperture of a shack-Hartmann wavefront sensor as set forth in claim 1 wherein said spot intensity crosstalk suppressor is integrated with a target surface of said image sensor as a unitary structure, and wherein a microstructure of said suppressor is fabricated directly on a protective window or target surface of said image sensor.
8. The device for suppressing cross-talk of spot intensities in sub-apertures of a shack-Hartmann wavefront sensor of claim 4 wherein the light absorbing material comprising the array of microstructures is a black polymer or metal oxide having a high absorptivity for the operating band and the optical waveguide structure is a micro-geometry capable of directing stray light to the absorbing layer or reflecting back to the original optical path.
9. The device for suppressing cross talk of sub-aperture spot intensity of a shack-Hartmann wavefront sensor as recited in claim 1 wherein the data processing computer is configured with a dedicated calibration module for generating a system calibration map for background noise and pixel response non-uniformity calibration of subsequently detected spot images by storing and processing standard spot image data.
10. The device for suppressing spot intensity crosstalk in a sub-aperture of a shack-Hartmann wavefront sensor of claim 1 wherein the device further comprises a sealed housing encapsulating the microlens array, the spot intensity crosstalk suppressor, and an effective target surface of the image sensor in an interior dark cavity environment to isolate external stray light interference.

Description

Shack-Hartmann wavefront sensor sub-aperture light spot intensity crosstalk suppression device Technical Field The invention belongs to the field of wavefront detection in adaptive optics, and particularly relates to a sub-aperture light spot intensity crosstalk suppression device of a shack-Hartmann wavefront sensor. Background The self-adaptive optical technology is mainly used for solving the problem that the wave front of the light beam is distorted due to atmospheric turbulence. The self-adaptive optical system is mainly divided into three parts, namely a wavefront sensor, a wavefront controller and a wavefront corrector, wherein the wavefront sensor is like an eye of the self-adaptive optical system and is responsible for detecting wavefront aberration. Hartmann wavefront sensor is widely used due to its simple structure and high precision, and is generally divided into a microlens array and an image sensor. The light beam is divided into a plurality of sub-light beams through the micro lens array to be focused on the image sensor, the sub-light spots can deviate to different degrees on the image sensor due to the influence of aberration, and the barycenter deviation of each sub-light spot relative to the reference ideal light spot position is calculated to reconstruct wavefront aberration. In the actual wavefront detection process, under the influence of external factors, a light spot focused on an image sensor by a micro lens is a diffraction light spot or an intensity dispersion light spot, along with the deviation of the position or the change of the size of the light spot, the energy of the light spot can be dispersed into an adjacent sub-aperture detection area, when the measured wavefront has high-frequency phase change or weak signal intensity, the light spots of the adjacent sub-apertures can overlap and interfere to influence the intensity distribution in the rest sub-apertures, and the calculation result of the actual centroid position of the light spot is error. In order to solve the problem, the common method is to remove noise by a global threshold method, an adaptive threshold method and the like, and only the area with the strongest center is left, so that the influence of weak-intensity crosstalk at the edge is reduced. However, for strong light and weak light signals, the denoising method can have a great influence on the original signal intensity distribution, and the centroid position of the original signal sub-light spot cannot be accurately extracted. Disclosure of Invention Aiming at the technical problems that the traditional Hartmann wavefront sensor is affected by the crosstalk of the light spot intensity, the centroid position of a sub-light spot cannot be accurately extracted, so that the wavefront detection precision is reduced. To achieve the above object, the present invention provides a shack-hartmann wavefront sensor sub-aperture spot intensity crosstalk suppression device, the device comprising: microlens array with focal length of Receiving the collimated light beam and dividing it into×Sub-beams, whereinFocusing on the effective target surface of the image sensor, wherein the number of sub apertures of the micro lens array is the same as the number of focusing sub beams; The light spot intensity crosstalk suppressor is arranged between the micro lens array and the image sensor and aligned with the sub apertures of the micro lens array one by one, and comprises a physical isolation structure formed by light absorption materials or light waveguide structures, and is used for carrying out three-dimensional physical isolation on light spots of the sub apertures of the adjacent micro lens arrays so as to suppress intensity crosstalk among the sub light spots; The image sensor is positioned at the focal plane of the micro lens array and is used for acquiring the sub-facula image processed by the facula intensity crosstalk suppressor; And the data processing computer is used for calculating the centroid position of the light spot in the sub-aperture of the micro lens array based on the sub-light spot image. Compared with the prior art, the invention has the following advantages: The device realizes three-dimensional physical isolation on adjacent sub-aperture light spots through the light spot intensity crosstalk suppressor, effectively suppresses intensity crosstalk between the sub-aperture light spots, improves centroid calculation precision and stability, is suitable for complex scenes such as strong light, weak light, high-frequency phase change and the like, and enhances the reliability and dynamic range of wavefront detection. Drawings In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the invention, and other drawings can