Henning Buelow

System performance of a nonlinear optical loop mirror used as demultiplexer for bit rates of 40 Gbit/s and beyond

Nonlinear optical fiber loop mirrors (NOLM) are attractive devices for multiplexing optical signals with bitrates of up to 100 Gbit/s and beyond. So far, less attention has been paid to the relation between design of the demultiplexer and the resulting system performance characterized by parameters like input power penalty and wavelength tolerance. Based on our own measurements of a polarization-independent 40 Gbit/s demultiplexer and in conjunction with a new theoretical approach modeling NOLM transmission and worst-case input power penalty of the demultiplexer, a device capable of 100 Gbit/s operation is analyzed. The survey illustrates the potential and trade-offs of the NOLM concept assuming a limited cw power of the switching wave. E.g., the calculations show that a 14.5 dBm booster EDFA together with a loop fiber length between 1 and 2 km allow low penalty drop rates (< 6 dB worst-case penalty) of the demultiplexed channel between 1.3 and 8.8 Gbit/s. Then 100 Gbit/s operation should be possible within a wavelength range of at least 5 nm.