New design of four-channel add-drop filters based on double-resonant cavity photonic crystals

Abstract

We proposed a new double-resonant cavity four-channel add-drop filter based on the in-plane type two-dimensional (2D) photonic crystal with square lattice. Through this novel double-resonant cavity, WDM signals can be coupled in or out of the bus waveguide with 100% add-drop efficiency while completely prohibiting cross talk between the bus and the add-drop waveguides for all other wavelengths. This device could be used as an optical add-drop multiplexer (OADM) in coarse wavelength division multiplexing (CWDM) applications.