Optical time-domain demultiplexing using semiconductor laser amplifiers

The huge bandwidth of optical fibres can be used for the transmission of high data rates multiplexed in the time-domain. The bottleneck will be the speed of the electronic signal processing at the termination of the transmission line. Employing optical signal processing at this point for demultiplexing the high speed signal, data rates of more than 100 Gbit/s can be transmitted. In this paper, we review two methods for optical high-speed time-domain demultiplexing, both using ultra-fast effects in semiconductor laser amplifiers (SLA). The first reported method uses fast four-wave mixing based on nonlinear gain dynamics in the subpicosecond range to build an optical AND gate. The second demultiplexing method uses a setup with an SLA in a loop mirror configuration. Fast gain saturation of the SLA is obtained by a short optical pulse. The principles of both methods are explained and system experiments during the recent two years are reported.