Post-fabrication trimming of athermal silicon waveguides

We experimentally demonstrate the post-fabrication trimming of polymer-coated athermal silicon waveguides by exploiting the photosensitivity of As2S3 chalcogenide glass to near-bandgap visible light. Our technique enables compensation of fabrication tolerances and modification of specific circuit functionalities after fabrication. Moreover, our athermal and trimmable waveguide technology is highly resilient to high optical power, and thus extremely appealing for nonlinear applications. Finally, it enables to fix the absolute wavelength and spectral response of silicon devices with extremely low dependence from temperature and power.