Deformable mirror iteration control method and system based on multi-element linear regression

Abstract

The invention discloses a deformable mirror iteration control method and system based on multi-element linear regression. The system is a closed-loop system composed of a computer, a deformable mirror, an attenuator and an interferometer. The method comprises the step of solving control parameters of a target surface shape, wherein the step of solving the control parameters of the target surface shape comprises the sub-steps that a plurality of sets of different random control parameters are applied to the deformable mirror, corresponding Zernike coefficient vectors are recorded, and then an influence function matrix G of the deformable mirror is solved on the basis that A equals to G*V; a set of initial iteration control parameters are applied to the deformable mirror and a correspondingactual surface shape is measured; the difference between the actual surface shape and the target surface shape is calculated, and whether the difference is smaller than a preset threshold or not is judged; if yes, the initialized iteration control parameters serve as the control parameters of the target surface shape; if not, a surface shape difference control parameter is solved on the basis thatA equals to G*V to update the iteration control parameters, iteration continues till the surface shape difference is smaller than the preset threshold.

Description

technical field [0001] The invention relates to the field of optics, in particular to a control method and a related system of a deformable mirror. Background technique [0002] The deformable mirror is one of the main components of the adaptive optics system, and the main components are the substrate, the actuator and the mirror. The actuator is deformed after the voltage is applied, and the mirror surface connected to it is deformed. Generally, the deformation amount is several microns. The wavefront aberration correction is realized through the surface shape change of the deformable mirror, and the wavefront aberration caused by the external interference of the optical system is compensated. The front distortion enables the system to obtain a target image close to the diffraction limit. For example, in the field of astronomical observation, due to the influence of atmospheric turbulence, the star image shakes and flickers. Correcting the obtained light wave information t...

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Problems solved by technology

At present, for the solution of the influence function matrix, it is generally to control a certain actuator alone, measure and record the change of the surface shape Zernike coefficient brought by a certain actuator, and then solve the influence function matrix with the principle of least squares, and then one by one The actuators are measured, ignoring the coupling of the actuators to each other, and the accuracy of the influence function is low

The traditional control method is to use the Hartman-Shack wavefront sensor to measure the wavefront distortion, and use the deformable mirror to reconstruct the conjugate wavefront to obtain the shape information of the deformed mirror. However, due to the influence of wavefront distortion measurement errors, the measurement accuracy is relatively low and The number of iterations is large, and the operation is complicated and inconvenient

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