High-contrast nulling in photonic meshes through architectural redundancy.

Abstract

We demonstrate a silicon photonic architecture comprising double Mach-Zehnder interferometers (DMZIs) designed for high-contrast photonic applications. This configuration significantly enhances the achievable extinction ratio of photonic integrated circuits (PICs), reaching levels exceeding 80 dB. By leveraging the tunable properties of DMZIs and implementing a systematic configuration algorithm, the proposed mesh effectively compensates for fabrication imperfections and mitigates non-idealities such as backreflections. Experimental validation on a silicon-on-insulator platform demonstrates the potential of this approach for applications requiring high-contrast nulling such as astronomical sensing.