All-optical switching with a nonlinear chiral photonic bandgap structure

A pump-probe optical switching mechanism that uses a nonlinear chiral photonic bandgap structure is proposed. The switching is achieved by shifting the bandgap of the structure; the chirality permits the use of the same frequency for the pump and the probe beam. The pump beam is never transmitted, so there is no dis; crimination problem. A new extension of the finite-difference time-domain technique is developed to simulate the propagation of an electromagnetic wave in a Kerr nonlinear chiral medium. (C) 1999 Optical Society of America. [S0740-3224(98)00212-4]. OCIS codes: 230.1150, 190.4360.