Two Dimensional (2D) circular Photonic Crystal Ring
Resonator (PCRR) based Add Drop Filter (ADF) is designed and
the impacts of rod shape with its filling fraction is examined to
evaluate the performance of the filter. The ADFs are devised
separately using rods of circular, hexagonal and square shape in
square lattice PC. For various values of rod’s cross sectional
dimension and shape, the resonant wavelength, coupling efficiency,
dropping efficiency, Q factor and passband width of the designed
filters are investigated through simulation. The calculated filling
fraction of a square, circular and hexagonal rods in the lattice
structure is 11.9006 × 10-12 sq.m, 13.1134 × 10-12 sq.m and
15.16 × 10-12 sq.m and their respective resonant wavelength is
1494 nm, 1504 nm and 1520 nm. It is observed that there is 1 nm
wavelength shift to longer wavelength while increasing the overall
filling fraction by 0.1233 × 10-12 sq.m. From the simulated results, it
is observed that the circular and hexagonal rods based ADF impart
better performance than square rod based ADF.
