Performance analysis of 2D PC Resonant Cavity based Demultiplexer for CWDM Applications

In this paper, four port Photonic Crystal Resonant Cavity based different demultiplexers by varying radius and by altering the refractive index of rods in resonant cavities are proposed for CWDM applications. The proposed structure has bus waveguide, dropping waveguide and four resonant cavities in each demultiplexer. The performance parameters of demultiplexer such as transmission efficiency, spectral width, channel spacing, quality factor and resonant wavelength are analyzed. The first structure can able to drop four different channels which are centered at 1499 nm, 1501.7 nm, 1504.2 nm and 1506.1 nm by altering the refractive index of rods in resonant cavities. The second structure can able to drop four different channels which are centered at 1595 nm, 1600nm, 1610 nm and 1615nm by altering the radius of rods in resonant cavities. The Plane Wave Expansion method is used to get band gap of the photonic structure. The 2D Finite Difference Time Domain method is utilized to compute the normalized transmission spectra of the demultiplexer