Post Fabrication Permanent Laser Trimming of Silicon Nitride Photonic Devices

We demonstrated the possibility of trimming the operating wavelength of nitrogen-rich silicon nitride racetrack resonators by exposing the devices to an ultraviolet laser. The results revealed that in a few seconds only, the resonant wavelength of fabricated devices could be tuned to any point within a free spectral range. This technique can also be applied to trim the response of any other silicon photonic device based on nitrogen-rich silicon nitride.