Abstract

As the demand for bandwidth increases, high-speed optical networks will become widely used in the core network. A WDM-OTDM hybrid system could be a promising candidate for high-speed core network communications. A key function for such systems is selective add/drop of a low bit-rate TDM data channel from an incoming high bit-rate WDM channel. Various methods of performing OTDM add-drop (OTDM-AD) have been demonstrated to date. All-optical techniques include using an Electro-absorption modulator to drop and insert a channel¹ and a monolithic InP Mach-Zehnder interferometer.² In this paper we present a robust method to perform all-optical OTDM-AD operation. Our method utilizes a Dispersion Shifted Fiber (DSF) based wavelength converter with 2R regeneration capability³ to drop a 10 Gb/s data channel from an incoming 40 Gb/s OTDM data signal and insert a new 10 Gb/s data channel in its place. This technique can be scaled to very high bit-rates, since the fiber nonlinearity response times are of the order of femtoseconds. Wavelength conversion over 13 nm has been demonstrated here and with appropriate fiber design, this range can be extended to over the entire C-band. This renders the add-drop multiplexer independent of the input wavelength over this range. Bit Error Rate (BER) measurement of the drop channel, the new inserted channel and the three through channels indicates a maximum power penalty of 1 dB. The three through channels and the new inserted channel were transmitted through 50 km of DSF without any additional power penalty.

© 2002 Optical Society of America