Bistable States ofs-Polarized Nonlinear Waves Guided by an Asymmetric Three Layer Dielectric Structure

Exact dispersion relations for TE-polarized nonlinear waves propagating in an asymmetric single film optical waveguide are derived. The system under consideration consists of a slab of thickness d with dielectric constant 2 bounded at the negative X-side by a linear medium with dielectric constant 1 and at the positive X-side by a nonlinear substrate characterized by the diagonal dielectric tensor 11 = 22 = 33 = 3 + α|E|2, α > 0 self-focusing medium. It is shown that for sufficiently small d/λ (λ is the wavelength) the nonlinear wave may exist only at power flows exceeding some certain minimal value. For sufficiently large d/λ we have found bistable states of s-polarized nonlinear waves provided that the total power flow is the control parameter and for power flows exceeding some certain threshold value a single waveguide mode (with mode order m = 0) occurs.