Self-Configuring GHz-Scale Multichannel Silicon Photonic Filter Using a Resonator-Assisted Discrete-Fourier-Transform Interferometer

Abstract

Reconfigurable multichannel optical filters (MOFs) witha highresolution are key devices for high-spectral-efficiency multi-carrieroptical transmission systems. However, very few on-chip MOFs reportedso far can meet the demands of high spectral resolution, device complexity,and scalable input/output ports. Here, we present a 10 GHz-bandwidthself-configurable silicon MOF using a resonator-assisted discrete-Fourier-transforminterferometer. With the help of ultra-low-loss silicon photonic waveguidesand low-phase-error Mach-Zehnder switches, the present chipfeatures a low excess loss, low power consumption, high port-countscalability, and sub-GHz spectral resolution. In particular, the presentMOF is capable of performing some specific filtering responses with,e.g., near-rectangular or sinc shapes. Furthermore, an efficient self-configuringapproach is also developed for the present chip to be programmable,so that different spectral responses can be achieved as desired byautomatically optimizing the settings of all the tuning elements,showing great potential for high-capacity optical communication networks.