Abstract

Semiconductor lasers have long been an exceptional test bench for the study of generic non linear dynamical phenomena such as bifurcations and chaos. Among the most striking phenomena studied in this context, dissipative solitons forming along the direction of propagation in mode locked lasers are both fascinating and potentially useful. Although there are important differences between the solitons observed in mode-locked lasers and those found in optical fibers, they share the fundamental mechanism at the root of their existence, which is the compensation between group velocity dispersion and self phase modulation (in addition to the compensation between dissipation and energy input in the mode-locking case). Therefore in both cases the optical power density is of crucial importance to reach the balance between Kerr or saturable nonlinearity and dispersion. In this contribution, we report on the experimental observation and theoretical analysis of the formation of phase solitons which form in a semiconductor ring laser under the influence of a coherent forcing beam. Contrary to any kind of dissipative solitons observed to date in semiconductor systems, these structures result fundamentally from the dynamics of the phase of laser light. They carry a chiral charge, ie they are associated with a 2pi rotation of the phase, which can occur in only one of two possible directions. In the idealized case of pure phase dynamics they can be related to topological solitons of the sine-Gordon equation[1].

© 2015 IEEE