Hannah Johnston

Hannah joined the CDT in September 2015 having previously completed a Masters in Physics at Queen's University Belfast.

CDT PhD Project:

Design Optimisation for an integrated optical device based on laser interactions with nanostructures

Supervisors:

Dr Bob Pollard, Queen's University Belfast

Professor Sandy Cochran, University of Glasgow

Numerous optical devices are now incorporating nanostructures which can be used in HAMR, biosensing or for optical communications. In order to use nanostructures for different applications, optimisations of the structures themselves and how they can be integrated into different devices with a viable source and detector must be investigated. In this project, we will begin by looking at a simple situation with a single source and a nanostructure surface. Maximising the sensitivity of the nanostructure to biological interactions at wavelengths corresponding to accessible laser lines will be achieved by tuning the dimensions of the nanostructures. Different energy sources will be researched during this project including planar light source and ultrasound. Characterisation of the device components will be undertaken in order to allow for optimisation; design of the device can be upgraded after completion of characterisation. The device can be upgraded for a multiplexed operation where a single planar source, such as a semiconductor laser, interacts with multiple spots on the nanostructure surface and how these spots can be imaged and analysed on a CCD or CMOS type detector.

Research themes touched upon in the project include low cost planar light wave circuit (PLC) platforms for coupling lasers into passive waveguides and suitable for volume manufacture. Thin film usage as tuneable metamaterial waveguide. Ultra-reliable semiconductor lasers operating in a hostile environment (high temperatures of around 100°C and potentially high pressure); the light source will need to be integrated into the device environment which could include heating to 100°C.