Simultaneous high speed OTDM add-drop multiplexing using GT-UNI switch

Introduction: The key functionality required in OTDM network nodes is add-drop multiplexing [1]. In an add-drop node a low bit rate single data channel will be separated (drop function) from an incoming high bit rate data stream. Simultaneously the remaining data channels should be left undisturbed (through function), and in the remaining vacant time slot a new channel can be added (add function). Recently, all-optical add-drop multiplexers operating at 40 Gbit=s based on cross phase modulation [2], a monolithic Mach-Zehnder interferometer [3], and an electroabsorption modulator [4] have been demonstrated. This Letter presents OTDM add-drop multiplexing in a GT-UNI switch operating at 80 Gbit=s, to the best of our knowledge the highest bit rate in OTDM networking so far. Several OTDM demultiplexing experiments with the GT-UNI switch have been reported e.g. [5], however complete add-drop multiplexing was not investigated. In our experiments we achieved error free operation without significant penalties of all add-drop node functionalities: drop, through, and add.