Measuring the Relationship between Grayscale and Phase Retardation of LCoS based on Binary Optics

A method for measuring LCoS phase retardation based on binary optics is introduced. Based on the diffraction efficiency formula of the binary grating, the relationship between grayscale and phase retardation is established. The method of designing experimental light path and testing with the aid of diaphragm is proposed, which is simple, intuitive, and insensitive to environmental perturbations. Finally, the feasibility of the method is verified based on the distribution of diffraction light spot. In addition, a method for detecting the specific position of the Gaussian light spot on the LCoS is also proposed, and the effectiveness of it is verified from experimental phenomena to theoretical derivation.