Improved electroabsorption demultiplexer by tandem-arrangement with semiconductor optical amplifier

An electroabsorption demultiplexer was improved by operating it in a tandem-arrangement with an optically controlled SOA. An increase of the maximum data rate from 40 Gbit/s to 80 Gbit/s was experimentally demonstrated. The main drawback of the proposed scheme is the need of an additional optical control. In this experiment a mode locked laser was used to control the SOA. However, it should be sufficient to use a gain-switched DFB-laser. The advantage of this scheme is that no electronic devices for frequencies higher than 10 GHz are required and no additional RF-source or RF-amplifier is needed for the control laser. The set-up is very robust, especially because it does not base on interferometric or polarization sensitive effects.