A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640x640 μm with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017λ at the reconstructed WF with wavelength λ . Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.

Date Published: 11 October 2010
PDF: 8 pages
Proc. SPIE 7828, Optics in Atmospheric Propagation and Adaptive Systems XIII, 78280P (11 October 2010); doi: 10.1117/12.865964

Published in SPIE Proceedings Vol. 7828:
Optics in Atmospheric Propagation and Adaptive Systems XIII
Karin Stein; John D. Gonglewski, Editor(s)