LCoS display phase self-calibration method based on diffractive lens schemes

Abstract

An experimental method to calibrate Liquid Crystal on Silicon (LCoS) displays by self-generating lens configurations on the studied device is proposed in this paper. On the one hand, a split-lens is displayed in the LCoS to self-generate an interference pattern from which the phase-voltage curve of the modulator is calculated. On the other hand, a microlens array is displayed on the LCoS, within a same experimental set-up, to implement a Shack-Hartmann (S-H) wavefront sensor, from which the display surface profile is retrieved. Specifically, by means of a feasible set-up, the proposed method allows measuring the deviation from flatness of the LCoS displays as well as to determine the phase-voltage response of phase-only SLMs. Experimental results demonstrate a linear tendency phase-voltage curve that ranges from 0 rad up to ∼6.28 rad, for the used light wavelength. Moreover, by extracting the LCoS phase distribution measured with the S-H configuration, the LCoS surface inhomogeneity is corrected by 95%.