Spatial solitons in a pumped semiconductor resonator

Bright and dark spatial solitons are observed in an optically pumped semiconductor resonator. The pumping allows to considerably reduce the light intensity necessary for the existence of the solitons and alleviates thermal load problems. Experiments are found to agree with calculations based on a simple large aperture semiconductor resonator model. The role of signs of the absorptive and reactive nonlinearities for soliton existence are discussed in relation with the nonlinear resonance effect, the tilted wave mechanism of pattern formation, and the sign of the population inversion.