Integration and Evaluation of Multichannel Photonic Crystal Wavelength Filters Consisting of Autocloned Ta2O5/SiO2 Multilayer Thin Films

We report on the fabrication of multichannel photonic crystal (PC) wavelength filters and their evaluation at wavelength division multiplexing (WDM) wavelengths. The devices utilize three-dimensional (3D) PCs consisting of Ta2O5/SiO2 multilayer thin films fabricated by the autocloning method. The 3D PCs serve as Bragg mirrors in the devices and finite-difference time-domain (FDTD) simulations of these mirrors revealed that their Bragg wavelength shifted by +19.8 nm as the in-plane lattice constant of the crystal increased from 400 nm to 800 nm. We fabricated these filters with a Ta2O5 cavity and obtained a wavelength shift of +24.0 nm.