Abstract: This paper applies one-dimensional finite difference time domain method（1D FDTD ）to investigate the polarization filter properties of one-dimensional photonic crysta.The calculated results obviously show that polarization of separating is good when the doped layer is in the neutral position;the greater the difference between the doped layer thickness and the periodic layer thickness is,the better the separating effect will be;the greater the difference between the refractive indexes,the more easily the bandgap will be formed;the greater the incidence angle is and the narrower the bandgap is,the better the separating will be.

Key words: one-dimensional dual photonic crystal, the finite difference time domain method, band gap, polarization filter properties