Generation, propagation, and amplification of dark solitons

W. Zhao and E. Bourkoff
Department of Electrical and Computer Engineering, The University of South Carolina, Columbia, South Carolina, 29208

The technique for generating dark solitons with constant background using guided-wave Mach–Zehnder interferometers is further examined. Under optimal conditions, a reduction of 30% in both the input optical power and the driving voltage can be achieved, as compared with the case of complete modulation. Dark solitons are also found to experience compression through amplification. When the gain coefficient is small, adiabatic amplification is possible. Raman amplification can be used as the gain mechanism for adiabatic amplification, in addition to being used for loss-compensation. The frequency and time shifts caused by intrapulse stimulated Raman scattering are both found to be a factor of 2 smaller than those for bright solitons. Finally, the propagation properties of even dark pulses are described quantitatively.