A real-time polarization-modulated Hartmann-Shack wavefront detection device

Abstract

The invention discloses a real-time polarization modulation Hartmann-Shack wavefront detection device, which uses the wavefront to detect the difference in polarization characteristics between the target light and the background stray light, and adds a micropolarizer between the microlens array and the light intensity detector Array, which performs 0°, 45°, 90° and 135° linear polarization modulation on the incident beam divided by the microlens array, and obtains the intensity distribution under different polarization modulation states at the same time, and calculates the polarization degree and polarization phase angle of the incident beam Equivalent polarization dimension information, and finally obtain the wavefront slope and restore the wavefront aberration, to realize the wavefront detection of the incident beam. Compared with the traditional Hartmann-Shack wavefront detection device, the invention transforms the wavefront detection from the intensity detection dimension to the polarization detection dimension, and uses the difference in polarization characteristics between the target light and the background stray light to separate the target light from the background stray light. Greatly improve the signal-to-background ratio and realize wavefront detection under strong background. The patented invention has compact structure and strong real-time performance.

Description

technical field [0001] The invention belongs to the technical field of wavefront aberration measurement, in particular to a real-time polarization modulation Hartmann-Shack wavefront detection device. Background technique [0002] Hartmann-Shack wavefront detection technology is a general classical wavefront phase detection technology, which is widely used in adaptive optics, astronomy, optical detection, biomedicine and other important fields. When the background stray light is not strong, the Hartmann-Shack wavefront detection technology can be applied not only to point source target detection, but also to extended target detection. When the signal-to-background ratio of the target detection is low or the background stray light is strong, the imaging information of the point source target or extended target in the sub-aperture of the Hartmann-Shack sensor microlens array will be submerged, and the contrast will be greatly reduced. Since then, the traditional centroid algo...

AI Technical Summary

Problems solved by technology

When the signal-to-background ratio of the target detection is low or the background stray light is strong, the imaging information of the point source target or the extended target in the sub-aperture of the Hartmann-Shack sensor microlens array will be submerged, and the contrast will be greatly reduced. Since the traditional centroid algorithm or cross-correlation algorithm effectively extracts the position offset of the imaging intensity information in a single sub-aperture, and leads to a decrease in the accuracy of wavefront detection or even failure

Therefore, the traditional Hartmann-Shack wavefront detection technology cannot be applied to wavefront detection under the condition of strong background stray light, and the application field and detection ability are greatly limited

Subtracting the fixed threshold (Jiang Wenhan et al., the detection error of the Shaker-Hartmann wavefront sensor [J]. Acta Quantum Electronics, 02:218, 1998), narrow-band spectral filtering (J.Beckers et al., Using laser beacons for daytimeadaptive optics[J].Experimental Astronomy,11(2):133,2001), field of view offset (C.Li et al.,Field of view shifted Shack-Hartmann wavefront sensor for daytimeadaptive optics system[J].Optics Letters, 31(19):2821,2006) and other methods can improve the signal-to-background ratio of wavefront detection to a certain extent, but they still cannot realize the application scenarios of strong background stray light wavefront detection.

[0003] The root of the above problems lies in the traditional Hartmann-Shack wavefront detection technology, whose wavefront error information extraction stays in the intensity dimension, and the target signal light is integrated with the background stray light, although it can be weakened to a certain extent by reducing the fixed threshold and other means. The influence of background stray light, but it is impossible to fundamentally distinguish the two

Images