Exploiting photosensitive As2S3 chalcogenide glass in photonic integrated circuits

In this contribution we present a new and efficient technique for post-fabrication trimming of chalcogenide (ChG) based photonic integrated circuits (PICs). The technique exploits the high photosensitivity of As₂S₃ glass to visible light radiation in order to induce a variation in the refractive index of the material, and therefore in the optical properties of ChG-based devices. The trimming technique enables not only to compensate for fabrication tolerances and restore desired functionalities, but also to provide a tool for the reconfiguration of photonic circuits. We demonstrate the trimming of PICs employing As₂S₃ core waveguides and As₂S₃-assisted silicon waveguides. Finally, to further show the wide versatility of this approach, we apply the technique to trim the response of As₃S₃ silicon waveguides covered with an additional polymer cladding layer, demonstrating simultaneous athermal operation and trimming functionality.