Temperature tuning of band edge resonant modes in one-dimensional photonic crystals

The transmission characteristics of Si-based 1D photonic crystals was investigated using transfer matrix method. As the temperature and wavelength dependence of Si refractive index induces band edge resonant modes that are temperature tunable, the average wavelength shift per Kelvin of the resonant mode with the largest group index was determined in the vicinity of the band edge. A general linear chirp structure consisting of a constant and chirp component was implemented. Using the simulated annealing algorithm, the structural parameters were optimized and it was found that the average wavelength shift per Kelvin of the band edge resonant mode can be enhanced by 28.9% with high transmission. It was also found that spatial chirping does not affect the wavelength shift. The enhancement was achieved by a uniform increase of PC layer widths. Tunable band edge resonant modes may be exploited in designing optical thermal sensing devices.