Multiple-photonic band gap of periodically chirped photonic crystal and its dynamic modulation

The periodically chirped photonic crystal structure has been proposed, in which the characteristic of multiple-photonic bandgap has been obtained by establishing the mathematical model of the structure using transfer matrix method, and the relationship model between the resonant wavelength and the thickness of each layer has been set up. Using inverse piezoelectric effect, the strain is performed on the photonic crystal and the thickness of each layer will change, which will result in the shift of multiple-photonic bandgap. From the simulation results, it has been shown that the full width at half maximum (FWHM) can be optimized and the quality factor (Q value) can been improved by adjusting the number of layers in the photonic crystal structure. Taking advantage of piezoelectric ceramic stacks, higher strain can be obtained under lower voltage compared with the general piezoelectric ceramic, the shift of wavelength can attain to 120 nm and the sensitivity is about 0.6 nm/V. The multiple-photonic bandgap characteristic and dynamic modulation regularity of the periodically chirped photonic crystal structure can provide some theoretical references for the design of tunable multi-channel filters.