With the rapid development of optical fiber, the traditional communication devices with electricity as the core is hardly to meet the needs of high-speed and large-capacity optical communication network. MEMS optical switch has become one of the important devices in all optical communication network due to its small size, easy integration and large capacity.
MEMS optical switch is based on Micro-Electro-Mechanical System(MEMS) technology, using the micromirrors to control and switch the optical path. Its function is shown in the following figure:
Application of OXC Optical cross connect is a matrix switch usually with N×N ports. The OXC can be used to construct a CDC ROADM (Colorless, Directionless, and Contentionless Reconfigurable Optical Add/Drop Multiplexer), as shown in Fig.1 .
OXC Constructed by 1×N Optical Switches The OXC can be constructed by 1×N optical switches, as shown in Fig.2. It requires 2N 1×N optical switch to construct a N×N OXC. Thus the size and cost of the OXC module increase rapidly with the incensement of port number N. OXC of this structure is usually limited to below 32×32 ports.
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.