In Optical fiber communication system, optical switch (OS) is mainly used to realize the physical switching of optical signal or other logical operation in optical path, and is often used as the key device of optical cross connection (OXC) technology to switch optical path.

The optical switch has one or more selectable transmission windows, which can be divided into various port configurations such as 2 x 2, 1 x N, M x N. Optical switch is widely used in optical fiber communication system with varied implementation techniques, including mechanical optical switch, thermal optical switch, acousto optical switch, electro optical switch, magneto optical switch, liquid crystal optical switch and MEMS optical switch, etc. Among them, mechanical optical switch and MEMS optical switch are two widely used optical switches at present.

What is Mechanical Optical Switch

Mechanical optical switches work by physically moving optical fibers with mechanical devices to redirect optical signals. By moving the prism or directional coupler, the input light is directed to the desired output port. There are three main types of mechanical optical switching: one is to switch the optical path using prism technology, another is by using reflecting mirror technology, and the third is by moving the optical fiber.

What is MEMS Optical Switch

MEMS optical switch is based on micro-electro-mechanical system, which uses optical micro mirrors or optical micro-mirror arrays to change the propagation direction of light beam to achieve optical path switching. The working principle of MEMS optical switch is quite simple. When the optical switching is carried out, the angle of MEMS micro mirror is moved or changed by electrostatic force or magnetic force, and the input light is switched to different output ends of the optical switch to realize the switching and on-off of the optical path.

With the rapid development of optical communication, the status of optical interconnection and optical switching as nodes of optical network is more and more important, and the application of optical switch is more and more extensive. MEMS optical switches have the advantages of compact size, fast switching speed and easy expansion, also featuring the advantages of mechanical optical switches including low insertion loss, low crosstalk, low PDL, high extinction ratio, easy for large-scale integration. The application of MEMS optical switches will be the mainstream in the development of high-capacity optical network switching.