Patent ID: 7941014

Claim:
An optical waveguide apparatus, comprising: a silicon nitride optical waveguide having a waveguide bend therein, with the waveguide bend having a width which adiabatically varies with distance between a minimum value of the width proximate to a pair of opposite ends of the waveguide bend and a maximum value of the width proximate to a midpoint of the waveguide bend; impurity-doped region comprising monocrystalline silicon or polycrystalline silicon located inside of the silicon nitride optical waveguide at a location proximate to the maximum value of the width of the waveguide bend, with the impurity-doped region extending from an inner sidewall of the optical waveguide only partway through the width of the optical waveguide, to change an effective index of refraction within the waveguide bend in response to a voltage applied to the impurity-doped region; and at least one connecting member silicon nitride optical waveguide proximate to the midpoint of the waveguide bend to provide the voltage to the impurity-doped region.