Poled glasses for optical devices

Abstract

Thermal poling is an efficient way to induce optical second-order nonlinearity in different types of glasses, which typically have macroscopic inversion symmetry. In this paper we present a study on the current dynamics during thermal poling of glasses and relate these results to the formation dynamics of the depletion region, which is closely linked to the induced optical second order nonlinearity. Based on a simple theoretical viewpoint, supported by experimental results, we propose that thermal poling of glasses, and space-charge formation in dielectrics in general, can be viewed as an ionic RC circuit. This, to some extent modified view on thermal poling in glasses, opens up new opportunities to study and control the depletion layer dynamics subsequently leading to better control of the thermal poling induced optical second order nonlinearity in glasses.