Design and analysis of tunable optical filter using different cavity shapes

In this paper, a two-dimensional photonic crystal based tunable optical filter having Si rods with different shape cavities, as H-shape, square and circular is designed and investigated. The shape of Si rods is also changed from circular to square and the shift in resonating frequency of filter is achieved. The area of each cavity has been kept constant for achieving the result. The filter is designed by creating defects based resonator and two line defect based reflectors. These defects are formed by simple removing the Si (dielectric material) rods. The designs proposed in this paper are suitable in optical circuits as wavelength shifting circuits. Also, they can be used as noise filtering devices for communication purpose.