Atmospheric Turbulence with Kolmogorov Spectra: Software Simulation, Real-Time Reconstruction and Compensation by Means of Adaptive Optical System with Bimorph and Stacked-Actuator Deformable Mirrors

Abstract

Atmospheric turbulence causes refractive index fluctuations, which in turn introduce extra distortions to the wavefront of the propagated radiation. It ultimately degrades telescope resolution (in imaging applications) and reduces radiation power density (in focusing applications). One of the possible ways of researching the impact of turbulence is to numerically simulate the spectrum of refractive index fluctuations, to reproduce it using a wavefront corrector and to measure the resultant wavefront using, for example, a Shack–Hartmann sensor. In this paper, we developed turbulence simulator software that generates phase screens with Kolmogorov spectra. We reconstructed the generated set of phase screens using a stacked-actuator deformable mirror and then compensated for the introduced wavefront distortions using a bimorph deformable mirror. The residual amplitude of the wavefront reconstructed by the 19-channel stacked-actuator mirror was 0.26 λ, while the residual amplitude of the wavefront compensated for by the 32-channel bimorph mirror was 0.08 λ.

Richardson–Lucy Iterative Blind Deconvolution with Gaussian Total Variation Constraints for Space Extended Object Images

“…In this section, the performance of the GRL iterative blind deconvolution algorithm will be tested against the RL-IBD algorithm via simulation experiments. The atmospheric turbulence degraded images are simulated based on the Zernike polynomials and Kolmogorov Spectra inversion methods [30,31]. The short exposure imaging was set to adjust the frozen flow hypothesis, and the adaptive optics was also used for tip/tilt compensation in simulation, more high-order aberrations were not corrected in simulated images.…”

Investigation of PZT Materials for Reliable Piezostack Deformable Mirror with Modular Design

“…Taking into account the fact that part of the range fails in overcoming the elastic forces due to the deformation of the reflecting substrate, in a piezoactuator deformable mirror, the local displacement will decrease by about 50% and will be >2 µm. Thus, these elements can be used in deformable mirrors of the piezoactuator type to correct for the phase fluctuations of the atmosphere of the Kolmogorov spectrum [77] on a path 1500 m long, a beam diameter of 250 mm, a structural constant of the refractive index of C n 2 = 10 -14 m -2/3 , and a coherence radius of 71 mm at a wavelength of 1064 nm [78][79][80].…”