The terahertz-frequency (THz) band of the electromagnetic spectrum lies between the infrared and microwave regions. THz sensors offer unique capabilities, including studying long-range structure in crystals (e.g., proteins and pharmaceuticals), quantum states in semiconductors, and spectral “fingerprints” of trace gases. The latter offers great potential for atmospheric and space research, as existing infrared or UV/visible techniques cannot distinguish a range of key gases in the Earth’s upper atmosphere or star-forming nebulas. Until recently, however, THz sources have been too large, complex and power-hungry for satellite applications.
In this project, the student will develop the “front-end” of a fully-integrated THz receiver, underpinning future satellite instruments. This will use THz local-oscillators, based on quantum-cascade lasers (QCL) — compact, yet extremely powerful semiconductor THz sources.
Objectives will include: developing and optimising satellite-compatible QCLs using state-of-the-art nanofabrication; designing precision-micromachined THz waveguides and antennas, and the first fully-integrated QCL-based THz receiver front-end, including thermal and optical modelling, and integration with a laboratory demonstration of a satellite payload.
This project is inherently interdisciplinary, coupling electronic and mechanical systems design with semiconductor-device physics. Precision micromachining, and receiver-system integration will be undertaken in collaboration with Rutherford Appleton Laboratory Space Department, and future atmospheric chemistry applications will be supported by ongoing engagement with the School of Chemistry.
Supervisors: Dr Alexander Valavanis and Dr Paul Dean.