Enhancement of the optical absorption in photonic crystal waveguides

In this paper, we present two new photonic crystal designs, giving the free space of the slabs around the cavities as well as the possibility of further absorption for the active layer of quantum dots. In the second design, the radius of the cavities gradually increases and the distance between them becomes smaller. Here, the removal of 4 small holes and replacing them with larger cavities are employed. The band structure is also presented because the presence of bands can be related to absorptions due to the defect structure. Because of the presence of bands that delay the movement of the wavelength of light, it is a plan for high absorption of its defect structure. The dielectric function of the quantum dots with a GaAs slab is calculated from the Maxwell–Garnet model and then replaced in Maxwell equations. The phenomena, namely slow light in the photonic crystal, cause increasing characteristics of optical structure.