Patent ID: 6911637
Filing Date: 2005-06-28
Classification: G01J,G02B

Abstract:
1. A wavefront sensor based on a differential Zernike filter comprising: an optical system for Fourier-domain filtering of an optical input beam to provide a Fourier-transformed beam; means for sampling the Fourier transformed beam; means for measuring the intensity of the sample of the Fourier transformed beam; means for providing a clock signal having electrical pulses; the optical system including a phase SLM to which the clock signal is applied for supplying equal but oppositely directed phase-shift distributions to the Fourier-transformed beam in response to said electrical pulses of the clock signal, to provide successive output beams having different intensity distributions; electronic circuitry for computing one or more electronic control input signals to the phase SLM from the intensity measurement of the Fourier transformed beam; means for measuring the intensity distributions of the output beams, and; an electronic processor for taking the difference between the different intensity distributions of the successive output means.