Design methodology for compact photoniccrystal-based wavelength division multiplexers

We present an extremely compact wavelength division multiplexer design, as well as a general framework for designing and optimizing frequency selective devices embedded in photonic crystals satisfying arbitrary design constraints. Our method is based on the Dirichlet-to-Neumman simulation method and uses low rank updates to the system to efficiently scan through many device designs. © 2011 Optical Society of America OCIS codes: 000.3860, 130.3120, 130.7408, 230.7408, 260.2110. Photonic crystal (PhC)-based circuits provide many at-tractive features for on-chip manipulation of light. A key ingredient to realizing planar integrated PhC circuits is a compact wavelength division multiplexer (WDM) used for separating different wavelengths of light. Exist-ing PhC WDM designs are based on resonators [1–5], waveguide couplers [6–8], or superprism effects [9–11]. Devices based on waveguide couplers or superprism ef-fects tend to have large areas. Resonator-based devices are compact; however, the key issue is to suppres