Effects of carrier phase on reflection of optical narrow-extent pulses from axially excited chiral sculptured thin films

Using a numerical time-domain method, we studied the reflection and refraction of optical narrow-extent pulses by linear and cubically nonlinear chiral sculptured thin films (STFs). The incident signal consisted of a carrier plane wave whose amplitude was modulated by a pulse envelope. The carrier phase and the nonlinearity of the chiral STF were found to have significant effects on both the shape and magnitude - as described by the instantaneous Poynting vector - of the reflected pulses, particularly with respect to the circular Bragg phenomenon exhibited by chiral STFs. The provided results point towards uses of the nanoengineered STFs in optical communication and sensing devices.