Direct calibration of liquid crystal spatial light modulators using a single-phase mask

Abstract

We propose and demonstrate, both theoretically and experimentally, a direct interferometric method for calibrating liquid crystal spatial light modulators. This method uses a single-phase mask to generate a zero-order light-free interference pattern after appropriate spatial filtering. The interference pattern is recorded and post-processed to determine the spatially dependent irradiance response of the liquid crystal display as a function of the gray levels of the associated image mask. This method allows global and local phase calibration without altering the optical setup. Our experimental results corroborate that, apart from the known dependence of the phase response on the wavelength of light, liquid crystal displays can exhibit inhomogeneous phase behavior due to imperfections or edge effects.