Transmission and Q-factor improvement in 2D square photonic crystal demultiplexer

Abstract

Our novel designed structure is a demultiplexer of 2D square photonic crystal (PC) of circular rods embedded in air in
which we have created three resonant cavities with different radiuses. So we have three channels based on these cavities
which have been implemented to realize the desired demultiplexer structure. The three radiuses of cavities deduce us to
obtain three different output resonant wavelengths; it means that this structure drops the desired wavelength depending on
the cavity radius. The refractive index n that we will use in this study have a constant value, n = 3.3763. In addition, we had
optimized this structure by the variation of the adjacent rods radiuses and positions for each of these cavities. The obtained
result is a structure with geometrically three different resonance zones. Then, we were being able to extract three resonant
wavelengths characterized by a high transmission power T and Q-factor which the mean values are 91% and 4247
respectively. We denote that this resulting T and Q-factor are higher than those investigated in bibliography.