Tunable multichannel filter in one-dimensional nonlinear ferroelectric photonic crystals

A tunable multichannel filter is proposed, which is based on a nonlinear ferroelectric photonic crystal made of iron-doped barium titanate, and can perform in the visible and infrared range. The filtering properties of the photonic crystal filter, including channel number and frequency, can be tuned by adjusting the thickness of the defect layer or by a pump light. The influences of the structural disorders caused by the random perturbations in the thickness of dielectric layers on the photonic crystal filter are analysed.