Fast analogue 2π phase modulation using a liquid crystal Pi-Cell

In this paper, we investigate the optical phase modulation potential of a nematic liquid crystal (LC) pi-cell operating in the so-called symmetric H (Hs) state. Experimental results of the optical phase modulation obtained using a phase-shifting Michelson interferometer are presented which are then...
Ausführliche Beschreibung

In this paper, we investigate the optical phase modulation potential of a nematic liquid crystal (LC) pi-cell operating in the so-called symmetric H (Hs) state. Experimental results of the optical phase modulation obtained using a phase-shifting Michelson interferometer are presented which are then compared with results from simulations carried out using Ericksen-Leslie continuum theory. The stability of the Hs state, which is limited, is investigated by adjusting the amplitude of the applied voltage and the duration of the voltage burst. To achieve full 2π phase modulation with 1 ms timescale in a reflective geometry (akin to that of a spatial light modulator), we employ a short burst voltage to drive the LC pi-cell into the Hs state, which shows excellent phase modulation capability, and the experimental results are found to be in good agreement with the results from simulations. Ausführliche Beschreibung