Transmittance spectrum of a defective one-dimensional photonic crystal with a protein solution

Abstract

In this work, we estimate the transmittance spectrum for a defective one-dimensional photonic crystal using the transfer matrix method. The cavity is filled with a protein solution, the refractive index of which changes with temperature. The cavity is surrounded by a semiconductor material (GaAs) and alternating SiO2 layers. Herein, we assume that the dielectric constant of GaAs is dependent on the applied pressure and temperature, and that the refractive index of SiO2 is obtained in accordance with the Sellmeir equation. In addition, when increasing the temperature and cavity thickness at a given fixed pressure value, a resonant peak may be observed within the photonic band gap, which shifts toward longer wavelengths and exhibits an increased quality factor. However, an increase in hydrostatic pressure causes a decrease in confinement of the defective mode within the cavity. The obtained results allowed us to design a protein sensor with high quality factors.