Christopher joined the CDT in September 2016, having previously completed an MSci in Physics at the University of Glasgow. In Semester 1 of 2016/17 he completed a short exploratory research project under the supervision of Professor Robert Hadfield - Characterization of superconducting thin films for integrated quantum photonics. In Semester 2 of 2016/17 he completed a short exploratory research project at Queen's University Belfast, under the supervision of Dr Amit Kumar - Investigating electronic properties of 2D materials using scanning tunnelling microscopy.
CDT PhD Research Project - Heterogeneous integration of III-V lasers to optical waveguides
This project aims to explore the integration of Ill-V materials to high refractive index optical waveguides for light delivery to plasmonic nanoantennae for use in heat assisted magnetic recording (HAMR). There are two main avenues of interest in coupling lasers into passive waveguides which are suitable for volume manufacture; heterogeneous and monolithic integration.
Heterogeneous integration techniques have caused great interest in recent years due to their compatibility with back-end processes. The fabrication of Ill-V devices and photonic integrated circuits can be independently optimised in different foundries and integration only occurs at the final stage (e.g. the Ill-V device are “picked and placed” onto the waveguide).
Monolithic integration intends to combine a laser to a waveguide using active-passive integration methods. Both quantum well intermixing, where the bandgap of a waveguide is selectively altered after fabrication while the bandgap of the laser, and the regrowth of a waveguide with a slightly different bandgap to the laser are viable approaches for light coupling and delivery to a nanoantenna.
The research activity will focus upon: the heterogeneous integration of a laser on a high index passive waveguide obtained from a Si-rich SiN material platform grown at low temperature, the development of active passive integration techniques for waveguides fabricated from materials such as AIGaAs, the design of photonic circuits for robust coupling between the Ill-V lasers and optical waveguides, and the assessment of the integrated devices.