Optical switches are widely employed in optical fiber communication systems. The approaches for an optical switch are variable, including mechanical optical switch, thermos-optic switch, acousto-optic switch, electro-optic switch, magneto-optic switch, liquid crystal optical switch, MEMS optical switch, et. al. MEMS optical switches are characterized by compact size, low power consumption and good scalability, which enable their wide applications.
Optical switch is a multiport device. The port configurations include 2×2, 1×N, N×N. Optical switch with N×N ports is usually called OXC (optical cross connect). According to the difference in port configurations, different MEMS chips are employed for realization of the devices. We will discuss optical switches with 2×2 and 1×N ports in this paper.