The transmission properties of a one-dimensional periodic structure with anisotropic defect layer is investigated using a
4×4 transfer matrix method. A layer of homogeneously aligned nematic liquid crystal is taken as a defect. We show that
the frequency and polarization of the defect mode is modified by changing the operating temperature and liquid crystal
orientation. Also the temperature dependent nonlinear response of the defect structure is investigated. It is shown that
the threshold intensity needed to achieve the bistability depends on the operating temperature. So, the structure can be
used as a thermal switch at the frequency near the defect mode.