New technique for wave-front reconstruction in optical telescopes

A new approach to wave-front sensing for adaptive optics systems is presented. The method, which explicitly accounts for measurement errors, is based on a phase-retrieval algorithm whose performance with respect to trapping and stagnation problems is improved by use of a suitable mathematical formulation. The algorithm allows the determination of the expansion coefficients of the wave front in terms of Zernike polynomials. A numerical analysis shows the effectiveness of the algorithm even when the maximum optical path disturbance value is greater than two wavelengths and the measurement error is quite significant.