Very low cost LCD-based optical spatial phase modulator

Liquid crystal display (LCD) is one of the optical devices that we see in our daily life. Its functionality is designed to operate in an amplitude modulation with up to a 32-bit resolution. As it is a low-cost spatial light modulator, this paper shows that two-dimensional (2-D) phase modulator can be obtained from this device. Experimental proof of concept using an off-the-shelf 60-USD 800x480-pixel LCD, a 633-nm wavelength laser diode, and a wavefront sensor shows that a linear 2-D phase modulator is obtained, offering a maximum 0.76-wave phase shift at a maximum grayscale value of 255. Varying digital bit control values from 0 to 255 leads to a very low optical power fluctuation of 1.53%.