Abstract

Wavelength-division multiplexing (WDM) filters desire a flat-top and unity pass-band bandwidth to ensure signal fidelity and to increase the tolerance to signal wavelength shifts [1, 2]. In silicon photonics such performance is typically obtained by utilizing e.g. a binary tree of cascaded Mach-Zehnder-like lattice filters [1] or coupled optical micro-ring resonators [2]. Moving away from conventional design solutions, it has been demonstrated that flat-top filter responses can be obtained by carefully designing the coupling and phase matching conditions between ultra-compact cavities in coupled photonic crystal (PhC) cavity systems [3]. However, designing PhC flat-top filters is not straight forward and may not give optimal solutions due to a limited design parameter space.

© 2015 IEEE