THERMAL TUNING OF AN OPTICAL DEVICE

摘要

Embodiments of an optical device, an array of optical devices, and a technique for fabricating the optical device or the array are described. This optical device is implemented on a substrate (such as silicon), and includes a thermally tunable optical waveguide with a high thermal resistance to the surrounding external environment and a low thermal resistance to a localized heater. In particular, the thermal resistances associated with thermal dissipation paths from a heater in the optical device to an external environment via electrodes and via the substrate are increased, while the thermal resistance between the optical waveguide and the heater is decreased. The heater element consists of a doped semiconductor layer with a rib waveguide (424) on top embedded in a surrounding cladding layer (416) having regions of high doping for improving electrical and termal contact between the electrode (418-1, 418-3) and via material (418-2, 418-4, 420-2, 420-1) and the heater part, (426-2, 422, 426-1).