Ultra Wide Band of Semiconductor Electrooptic Modulator Devices for high Transmission Capacity

The rapid growth of data traffic, caused mainly by increasing use of the Internet including recent expanded use of multimedia services and wireless access, has stimulated the demand for high-capacity photonic network systems. High capacity optical networks are based on a combination of wavelength-division multiplexing (WDM) and time-division multiplexing (TDM) for purposes ranging from long distance transmission between nodes to short-reach optical links such as metro/access links. Moreover, the next generation networks (NGN) are not far away from us and the 100 Gbit/sec Ethernet is also in progress. All of these will inevitably need transmitters which can operate above 40 Gbit/sec. The maximum direct modulation bandwidth in semiconductor lasers in limited to a few GHz. The frequency chirp associated with high-speed direct modulation of laser diodes above a few Gbit/s has become a clear problem and results in serious consequences in high data rate long-distance optical-fiber transmission systems. The electrooptical modulator is the only choice for transmitters operating at bit rates beyond 10 Gbit/sec in a long haul transmission system. As well as we have investigated the ultra wide band of semiconductor based Electroptic modulator devices within using Shannon transmission technique for high capacity optical communication systems over wide range of the affecting parameters.