Optical switching in nonlinear chiral distributed Bragg reflectors with defect layers

We present a new iterative approach to obtain the electric field from the displacement field for a chiral medium with Kerr nonlinearity. In a study recently reported [ P. Tran , J. Opt. Soc. Am. B16, 70 (1999)], this is done by a Newton–Raphson root-finding approach, which requires the initial guess to be near the solution. The new approach eliminates this requirement, and therefore it is more robust. We also study an all-optical switch using a chiral nonlinear thin-film Bragg reflector with two defect layers. This switch has a lower switching threshold than one using a perfect Bragg reflector. Since the switching operation is dependent on the shifting of the defect mode and not on the band edge (as in the case of a perfect multilayer structure), it should be less susceptible to manufacturing errors.