The strong confinement provided by plasmonic resonances has extended optics down to the nanoscale, allowing an unprecedented control over the interaction between light and matter. This could have far reaching applications in the development of ultra-compact and novel op- toelectronic devices. However, for commercial implementation of these plasmonic devices to become a reality there needs to be a shift toward designs which are compatible with the materi- als and processes of the established semiconductor industry. This is the overarching aim of the work presented in this thesis; here plasmonic devices are developed around the semiconductor on insulator architecture using a simple monolithic fabrication processes.
Two waveguides are proposed and analysed, both produced through a single lithography step where a metallic slot or strip is formed on top of an SOI wafer. This process circumvents the etch step required to produce the waveguides used in silicon photonics. Despite this exceptionally simple fabrication procedure the designs support bound modes with areas as small as λ20/1000. Importantly, the mode size can be controlled through the width of the slot or strip and though careful design this can be used to effectively nanofocus light from larger low loss modes down to the nanoscale. The slot design is demonstrated experimentally with widths as narrow as 10nm.
Following this, a similar design is implemented as a plasmonic laser. Here the SOI wafer is swapped for a suspended membrane of GaAs to provide the necessary gain. Lasers with slot widths as small as 100nm are demonstrated experimentally. A final device design is also discussed, where a highly effective cavity is formed through an array of metal resonators coupled to a semiconductor slab.
The devices demonstrated in this thesis aim to provide a platform that allows the unique capabilities of plasmonics to be easily integrated with existing technologies.Open Acces
