Professor Jo Shien Ng
Departmental Director of Research & Innovation
Tel: +44 (0)114 22 25173
ORCID ID: 0000-0002-1064-0410
Research Group: Semiconductor Materials & Devices
I received my B.Eng. degree and Ph.D. degrees in electronic engineering from the University of Sheffield, in 1999 and 2003, respectively. After a postdoctoral position within the EPSRC National Centre for III–V Technologies (now part of EPSRC National Epitaxy Facility) for material and device characterization, I became a Royal Society Research Fellow from 2006 to 2016. I am currently Professor of Semiconductor Devices.
My research is focused on developing a type of light sensors capable of measuring the weakest possible light signals.
There is a wide range of applications that rely on detection of the weakest possible light signal. An example is quantum cryptography (whose encryption key is made up of these very weak light), which currently offers the ultimate encryption safety.
Other key applications for highly sensitive light sensors are high-speed optical communication systems, laser-based ranging (autonomous vehicles and high-resolution geographical mapping), medical imaging (X-ray computed tomography), and non-contact temperature measurements. These systems depend on detecting light so weak that each signal comprises only hundreds or photons (which make up the light) or even down to a single photon.
I am particularly interested in using avalanche photodiodes (APDs) to detect the very weak light. This semiconductor device senses light and gives electrical current that varies with the light intensity. A process called avalanche gain (similar to how snow avalanche grows in size as it accelerates down a snow-covered mountain) in the APDs amplifies the electrical current, improving the system’s performance in terms of signal-to-noise ratios.
My current research themes include Si SPADs for detecting visible light from Raman spectroscopy; low-noise APDs for high-speed optical communication systems; measurements of avalanche gain and noise from novel materials; simulation models for APDs and single photon avalanche diodes (SPADs).
Research income since Oct 2006 is £3.9 million, made up of Principal Investigator (£1.6 million) and Co-investigator (£ 2.3 million approportioned).