Angular and Thermal Dependence of Defect Modes in Si-Based One-dimensional Photonic Crystal

The effect of temperature and angle of incidence on defect modes in one-dimensional photonic crystal structure for TE and TM polarizations has been studied in 5-9µm wavelength region. A symmetric Si/air multilayer system, [(Si/air)5Si(air/Si)5] has been considered in this communication. The refractive index of Si layer is taken to be dependent on temperature and wavelength simultaneously. As the refractive index of Si layer is a function of temperature of medium as well as the wavelength of incident light, this results to the tuning of defect modes. As defect modes are function of temperature, one can tune the defect modes to desired wavelength. The defects modes can also be tuned by angle of incidence for both polarizations. This type of tunable filter may be used as thermal sensing optical device etc.