Optical switches are among key devices for implementation of DWDM in optical networks. There are a number of technologies available to realize optical switches, including Micro-Electro-Mechanical System (MEMS) switches, Bubble-Based Waveguide Switches, Liquid Crystal on Silicon (LCOS) Switches, Electro-Optic Switches, and Thermo-Optic Switches. Among these technologies MEMS has received particular
attention in recent years, initially using 2 dimensional (2D) switches and later progressing to 3D switches. This paper evaluates Liquid Crystal on Silicon (LCOS) as an alternative to MEMS for implementation of optical switches. The opportunities and
challenges for LCOS in optical networking are discussed. Issues related to availability of LCs, switching speeds, voltage requirements, scalability, wavelength range, packaging and crosstalk are considered.