| The purpose of this thesis was to explore the possibilities for monolithic integration of widely-tunable all-optical wavelength converters using an offset quantum well integration platform in Indium Phosphide.; Tunable wavelength converters represent one of the enabling technologies for future Wavelength Division Multiplexed (WDM) optical networks, where the switching and routing functions are expected to be pushed into the optical layer. In particular, all-optical wavelength conversion techniques, that allow for transcription of data from one wavelength to another without passing through electronics, represent an attractive solution due to their better scalability with bit rate, simple design, low power consumption and potential for monolithic integration, when compared to the classical optical-electronicoptical approaches. TAOWC photonic integrated circuits (PIC) that were designed, fabricated and characterized as part of this project employed widely-tunable Sampled-Grating Distributed Bragg Reflector (SGDBR) lasers monolithically integrated with all-optical, Mach-Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) based wavelength converters.; Important aspect of the monolithic integration are covered in this thesis: the benefits and challenges of monolithic integration, properties of the integration platform used and the tradeoffs in the different component designs. Analysis and guidelines for TAOWC device design are presented. This covers the main functional building blocks (laser, optical amplifier, wavelength converter) of the PIC, as well as the photonic interconnections (passive waveguides, light couplers), with a critical role to optically link all of the building blocks together into a single PIC. Special attention is given to the analysis of possible sources of coherent back reflections into the on-chip laser and reflections mitigation through device/component design, since reflection can be fatal for the device performance.; Finally, results of the experimental characterization of the device operation are presented, together with a demonstration of the optical routing function. In this work, we have demonstrated regenerative, error-free wave length conversion with low power penalties for bit rates up to 10 GB/s, with high input sensitivities (-5 dBm for 10 Gbps, -10 dBm for 2.5 Gbps), significant output powers of 0 dBm for the converted signal, up to 10 dB of signal gain, over 45 nm input and 35 nm output wavelength range. |
