Tunable multichannel filter in nonlinear ferroelectric photonic crystal

A tunable filter with multichannel is proposed based on a nonlinear ferroelectric photonic crystal made of rhodium doped barium titanate. The filtering properties of the photonic crystal filter, including channel number and frequency, can be tuned by adjusting the thickness of defect layer or by pump light. The dynamical shift of channels with pump intensity is studied in detail. The channel shifts about 90 nm under the excitation of 75 MW/cm2 pump light. The influences of structural disorders caused by random perturbations in the thickness of dielectric layer or air layer on the photonic crystal filter are analyzed.