Frequency analysis of wavelength demultiplexers and optical filters with finite 2-D photonic crystals

A wavelength demultiplexer made of 2-D photonic crystal capable of simultan eously separating many channels from WDM light is analyzed in order to stud y the properties and clarify the design parameters. Numerical analyses are carried out for the optical filter structure and the demultiplexer structur e which consists of several filters and waveguides carved in the crystal. T he results of this paper show the considerations regarding the frequency tu ning, the device size, the bandwidth and integration of filters. Further mo re, for a photonic crystal filter, a method for realizing a flat-top pass-b and generally required from the dense-WDM systems is presented and its prop erty is shown. The calculation method is the scattering matrix method which is proper to the analysis of the frequency domain in a 2-D photonic crysta l with finite size and with some defects.