TRANSPARENT SWITCHES
INTRODUCTIONA large communication network can be pictured as having two main parts: a transmission plant and switching facilities. The first transports traffic between network nodes, while second routs traffic over the transmission plant to get it from the source to destination. In recent years optical transmission technology has progressed very faster.
Transparent switches are the switches in which optical switches are routed without intermediate conversion into electronic form.
These switches are also called photonic or transparent switches .Of course these switches are cheap and capable of dealing with thousand of inputs and outputs that traditional electronic switches handle so well. Several approaches are being explored for making these devices. These include array of tiny movable mirrors, known as microelectromechanical systems, or MEMS, and unit based on holographic crystal, liquid crystal total internal reflection and polarization dependent materials. The problem is to figure out which all-optical switching technology to use in what application. Optical switches are sometimes referred as O-O-O switches. Unlike O-E-O switches, present all optical switches are not capable of separately routing each of low data streams carried by a single input wavelength.