Enhancement of transmission in 1D thermal tunable metallic photonic crystal filter with exponential gradation thickness

Abstract

Using the transfer matrix method, the transmission of 1D thermal tunable metallic photonic crystal (PC) filter with symmetry exponential gradation of thickness has been examined in this article. For the purpose of making this structure, three different materials silicon, silica, and silver have been used. The refractive index of silver is considered as a function of temperature and wavelength. The dependence of the silicon refractive index on the wavelength is also considered in calculations. The effect of the variation of temperature and incident angle on the transmission peaks has been investigated. By increasing the temperature, the transmission peaks in the position of defect modes move toward the larger wavelength at a given incident angle. When the incident angle is increased, however, they shift toward the shorter wavelength in both polarizations. The height of transmission peaks decreases linearly by increasing the temperature. Results are compared with those obtained in our previous work. The position of the transmission peaks in the structure with the exponential gradation of thickness is higher than the non-graded and linear graded, and the transmission peaks are sharper in TE polarization.

Graphical abstract