Dependence of photonic defect modes on hydrostatic pressure in a 2D hexagonal lattice

The plane wave expansion method is used to investigate the effects of hydrostatic pressure on the photonic band structure in a two-dimensional hexagonal lattice composed cylindrical air holes embedded in a GaAs background. We found that the hydrostatic pressure modifies the optical response of the crystal. While increasing the pressure, the photonic band structure for both transverse electric (TE) and transverse magnetic (TM) polarizations, exhibit a shift to high-frequency regions due to a decrease in the dielectric constant of the semiconductor. Using the supercell technique, the numerical results exhibit that both the position and width of the photonic band gap for both polarizations remain unchanged while eliminating a cylindrical air hole. Additionally, we observe defective modes whose energies increase with an increase in hydrostatic pressure inside the photonic band gap.