Modelling of all-optical symmetric Mach-Zehnder switch with asymmetric coupler

Ultra high-speed optical network is developing rapidly as growing capacity demand in telecommunication system is increasing. In these networks, it is desired to carry out switching, routing and processing in optical domain to avoid bottlenecks of optoelectronic conversions. Optical time-division multiplexing (OTDM) technique is one option to implement all optical networks. It provides a single data stream at a very high rate (>100 Gbits/s) using a single wavelength. These networks will be based on optical packet switching. The success of these networks depends on how well switching and routing are being done at this very high speed. An all optical switch based on symmetric Mach-Zehnder (SMZ) with asymmetric coupler (60:40) is proposed. Its characteristics and switching window profiles will be investigated. The results show that symmetric Mach-Zehnder (SMZ) with asymmetric coupler gives a better contrast ratio rather than symmetric Mach-Zehnder (SMZ) with normal 50:50 coupler.