Wavefront detection method based on spatial frequency domain reference

Abstract

The invention discloses a wavefront detection method based on spatial frequency domain reference, and relates to the technical field of wavefront detection. An optical element is used for carrying outtwo-time Fourier transformation on a light field of a light beam to be detected; an asymmetric crosshair is introduced in a spatial frequency spectrum surface after the first Fourier transformation to serve as a reference for modulation of the light field; a single near-field intensity map after the second Fourier transformation is collected; the single near-field intensity map is divided into aplurality of sub-regions; a wavefront slope of each sub-region is calculated; and wavefront distribution of the light beam to be detected is reconstructed through a region integral algorithm. Comparedwith a traditional wavefront measuring technology, a wavefront measuring result is irrelevant to an optical path aberration after the crosshair; no special calibration is needed; only the single near-field intensity map needs to be collected, and then the sub-region wavefront slope extraction and the wavefront reconstruction can be carried out; the real-time performance of wavefront measurement is relatively high; the implementation mode is simple; meanwhile, a special wavefront sensor does not need to be introduced; and the method is easy to integrate for use and high in universality.

Description

technical field [0001] The present invention relates to the technical field of wavefront detection, in particular to a wavefront detection method based on spatial frequency domain reference. Background technique [0002] The wavefront of the beam is an important parameter to describe the characteristics of the light field, and it is also an important information carrier. Obtaining the wavefront of the beam through the wavefront measurement technology can not only evaluate the physical properties of the light field, such as transmission ability, focusing ability, etc., but also obtain a lot of physical information, such as atmospheric turbulence distribution, optical element surface shape, optical system aberration, biological Tissue phase characteristics and flow field distribution characteristics, etc. At present, wavefront detection technology is widely used in adaptive optics, astronomical observation, optical component processing, laser system beam quality assessment, b...

AI Technical Summary

Problems solved by technology

Interferometric wavefront measurement technology is characterized by extremely high detection accuracy, and is often used in surface shape detection of optical components and high-precision beam wavefront detection; Hartmann-Shack wavefront measurement technology divides the beam through a microlens array, Test the slope of each sub-beam to reconstruct the wavefront. Its structure is simple and solid, and it has been widely used in the fields of laser technology and astronomical detection. Curvature wavefront sensing technology can effectively detect low-order wavefront distribution, and is often used in The adaptive optics system of the electric deformable mirror improves the system control bandwidth; the mode wavefront sensing technology directly calculates the coefficients of each order aberration mode according to the distribution of light intensity, which can improve the wavefront detection speed; the phase difference wavefront measurement technology analysis The light intensity distribution at the focus and defocus positions is used to invert the wavefront, but due to the complexity of the algorithm, the real-time performance of the test needs to be improved; the pyramidal wavefront sensing technology uses the light beam at the focal plane of the prism to perform spectroscopic measurement for calculation and calculation, and the response speed is fast , the detection accuracy is high, and it has achieved important applications in the field of astronomical observation; the wavefront iterative reconstruction technology based on diffraction transmission is to restore the wavefront by testing the distribution of diffracted light intensity and using iterative algorithms such as G-S. Although the test system is simple, the wavefront The front inversion is slow and the convergence cannot be guaranteed

Images