Integrated optical devices (e.g., photonic integrated circuits) are well suited to applications in various technologies such as telecommunications, instrumentation, signal processing and sensors. In operation, photonic integrated circuits use optical waveguides to implement devices, such as optical switches, optical couplers and wavelength multiplexers/demultiplexers, for example. Such waveguides, when integrated with a photonic integrated circuit, are typically implemented as solid dielectric light conductors, which are fabricated on a substrate in a very similar fashion as semiconductor integrated circuits are manufactured. Waveguides transmit light around optical circuits and also connect to external optical waveguides, such as optical fibers, typically by direct physical abutment of the fiber with the waveguide. However, in such a configuration, a mode mismatch results between the integrated waveguide and the optical fiber.
As such, improvements are needed.