Optimization of Dense Wavelength Division Multiplexing demultiplexer   with 25GHz uniform channel spacing
  In this paper,we propose a four channel Dense Wavelength Division Multiplexing demultiplexer with two dimensional photonic crystal square resonant cavity that fulfill the ITU-T recommendation of G.694.1 DWDM systems.DWDM demultiplexer consists of a waveguide and Microscopic Square Resonant (MSR) cavity to enable filtering of the desired wavelength. The MSR cavity design has inner rods, outer rods and coupling rods. As the radius of the inner rod in MSR cavity changes, the cavity has the ability to filter different ITU.T G.6941 standard wavelengths like 1555.3 nm, 1555.5 nm, 1555.7 nm, and 1555.9 nm with 0.2 nm / 25 GHz channel spacing. From the simulation of various wavelengths, helps achievement of the quality factor of 8000, uniform spectral linewidth of 0.2 nm, transmission efficiency of 100 %, crosstalk of -42 dB and footprint is about 395 micro meter square. 
Venkatachalam Rajarajan Balaji, Mahalingam Murugan, Savarimuthu   Robinson
physics.optics