Contour plots of the transmission spectrum of the 1D-FGPC (T₃) structure as a function of the permittivities and thicknesses in the case of σ_g ≠ 0 and blue light frequency for the dielectric material A (a) and the dielectric material B (b). The waves are normal incidence to the interfaces and temperature and chemical potential are chosen as T = 300 K and μ_C = 0.2 eV.