VECTOR DARK SPATIAL SOLITONS

The dark spatial solution of TM type is shown to exist in a uniform selfdefocussing nonlinear medium in the range of the beam effective index n(eff) from 0.82n0 to n0 of the linear refractive index of the medium. This contrasts with the dark spatial soliton of TE type which exists over all the possible values of n(eff) ranging from 0 to n0. The field profile of this TM dark wave is also found to depend on the beam effective index, deviating from the hyperbolic tanh function of TE type with decreasing n(eff).