| Semiconductor optical amplifier based all-optical wavelength converters (SOA-WCs) in Indium Phosphide have received a lot of attention for their wide range of potential uses in all-optical networks, including wavelength routing and signal regeneration. As semiconductor devices, their ability to be monolithically integrated with other components on-chip (e.g. lasers, modulators, and filters) makes them appealing for increased system stability, reduced inter-component loss, and lower packaging costs.;Past work with SOA-WCs at UCSB has produced a variety of integrated tunable wavelength converters, each incorporating tunable lasers on-chip. These devices provide greater than 35nm of output tuning, but require an external tunable filter to remove the input signal at the output of the SOA-WC. Consequently, because filtering is not integrated, tunable SOA-WCs cannot be cascaded with a number of active and passive components on chip, which limits their potential for large-scale integration. This thesis focuses on the application of broadband spatial filtering techniques to tunable SOA-WCs, for filter-free wavelength conversion and cascaded SOA-WC architectures.;Single-stage spatially filtered tunable SOA-WCs are developed first, and are shown to provide greater than 20dB of input signal suppression at the output of the device, allowing filter-free, error-free operation at 10Gbps. Spatial filtering is then applied to realize two-stage SOA-WCs, where suppression of the input signal allows two tunable WCs to be cascaded on-chip. The two-stage device is shown to allow wavelength conversion for cases where the input wavelength is equal to the output wavelength, as well as improving dynamic range to 15dB at 2.5Gbps with no adjustment in the operating conditions. By utilizing a tunable signal that's internal to the chip, the two-stage converter is also proposed as a viable architecture for operating spectrally-narrow devices (e.g. gratings, filters) over a broad input and output wavelength range.;Finally, the two-stage SOA-WC is modified to create an all-optical push-pull SOA-WC. With the monolithic push-pull WC, spatial filtering and routing of the input and converted signals at the output of the first WC stage are used to optically modulate the second SOA-Mach Zehnder interferometer (MZI) WC stage in push-pull mode. This is shown to allow full pi phase swing in the SOA-WC and improve pattern dependence at 10Gbps. Low-loss concave total-internal reflection (TIR) corner mirrors are also developed, and used to fold the push-pull WC for compact layout. |
