Voltage-Tunable vapour detector using optical beam shifts in a magneto-electric multilayered structure

摘要

We investigate the spatial and angular lateral shifts of a Gaussian light beam reflected from a structure consisting of a nematic liquid crystal cell sandwiched between semi-transparent indium-tin oxide electrodes and deposited on a magneto-electric yttrium-iron garnet film grown on a non-magnetic dielectric gadolinium-gallium garnet substrate. We show that the external voltage applied to the liquid crystal cell allows an efficient tuning of the beam shifts. We propose a scheme for a vapour detection technique based on the measurement of the lateral shift variations induced by tiny changes of the relative permittivity of the air surrounding the system.