  In this paper, we have firstly proposed a new one-dimensional variable
frequency photonic crystals (VFPCs), and calculated the transmissivity and the
electronic field distribution of VFPCs with and without defect layer, and
considered the effect of defect layer and variable frequency function on the
transmissivity and the electronic field distribution. We have obtained some new
characteristics for the VFPCs, which should be help to design a new type
optical devices.
