Midband solitons in nonlinear photonic crystal resonators

We investigate cavity solitons in nonlinear photonic crystal resonators, i.e., in the nonlinear resonators with the refractive index periodically modulated in the transverse direction. We study several families of the cavity solitons: (1) "normal," and (2) "staggered" solitons, similar to those in conservative nonlinear photonic crystals; (3) "midband" solitons, predicted recently in dissipative nonlinear photonic crystals [Phys. Rev. Lett. 91, 053901 (2003)]]; and (4) "double head" cavity solitons not reported before. We investigate the solitons by (1) numerically solving the full microscopic model explicitly accounting for the small scale refractive index modulation, and (2) adopting a "mean field" approximation, e.g., eliminating the small scale refractive index modulation.