<title>High-speed optical demultiplexing</title>

Abstract

ABSTRACT Optical demultiplexing is an important technique for retrieving data from high speed optical transmissionsystems. In this technique, the data bits are first demultiplexed to much lower data rate bit streams fromwhich the information is retrieved using conventional electronic techniques. We have performed opticaldemultiplexing experiments for 80 Gb/s and 160 Gb/s optical time division multiplexed signals. Theseexperiments include data generation, clock recovery and optical demultiplexing to lower data rate ( 10 and20 Gb/s ) bit streams. The optical devices used for demultiplexing are, LiNbO3 modulators, four wavemixing in semiconductor amplifiers, and semiconductor amplifier based Mach-Zehnder interferometers.The high speed performance limits of these devices would also be discussed. INTRODUCTION Future communication networks will require total transmission capacities of few Tb/s. Such capacitiescould be achieved by wavelength division multiplexing (WDM) or time division multiplexing (TDM)[l-5].Although WDM technologies could be employed to achieve these capacities using single channel rates of10 or 20 Gb/s, it is very likely in the future these rates would approach 100 Gb/s or higher. Thus bothWDM and TDM technologies are going to coexist. The speed of electronic circuits necessary to count thebits ( 1' 5