Single LiNbO 3 slab integrated one-input/N-output electro-optic switch

Abstract

Integration of optical systems is important in practical applications for enhanced compactness and stability, particularly for optical switch. In the previous reports, 1×N electro-optic switches were constructed by the assembling of discrete E-O elements. The aim of this paper is to develop a 1×N switch integrated in a single slab of LiNbO₃, which consists of an array of electro-optic polarization modulators between the interfaces for total-internal reflection. Due to the double refraction effect, the ordinary ray and the extraordinary ray have different reflections. From different switching states of modulators, the internally double reflection along the sequential interfaces of a crystal can lead to different directions of the output beam. On this basis, a 1×N optical switch is designed, which is a crystal slab of 2 refractive interfaces for beam input and output, 4 reflective interfaces for total-internally double reflection, and N-1 E-O modulators with pairs of electrodes. A voltage on the <i>n</i> pair of electrodes will induce output beam onto the <i>n</i> angular position. The suggested 1×N switch is simple and compact in construction, low in loss and insensitive to environment. An experimental 1×4 switch is demonstrated, too.