Electronic & Electrical EngineeringOptical Sensors

Optical Gas Sensing

Principal Investigators: Prof Walter Johnstone & Dr Michael Lengden

The optical gas sensing group has been developing gas sensors for harsh environments for over 20 years.  Our research includes:

  • new approaches to signal analysis in tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS)
  • high power optical amplifier development for remote sensing and PAS
  • difference-frequency generation and QCL sensors in the mid-IR
  • cavity ring-down spectroscopy for flame diagnostics
  • high temperature optical spectroscopy

Of particular note is the development of truly calibration-free TDLS techniques for the simultaneous measurement of both pressure and concentration, and extension of these to high-temperature applications. 

Photoacoustic Imaging

Principal Investigators: Prof Deepak Uttamchandani & Dr Gordon Flockhart

Photoacoustic imaging (PAI) focuses pulsed laser light deep into tissue samples thereby generating a wideband acoustic wave (via an optical-thermal-mechanical process) which is detected ultrasonically to generate an image. Our research aims to investigate the potential of advanced techniques for optical laser generation of ultrasound and photoacoustic imaging to provide additional information about the tissue under test.  We are also interested in research investigating the integration of miniaturized piezoelectric MEMS arrays for photoacoustic detection.

Optical Fibre Sensors

Principal Investigators: Dr Gordon Flockhart & Prof George Stewart

Optical fibre sensors offer unique attributes compared to conventional electrical sensors.  They are small size, low weight, can operate in harsh environments and are immune to electromagnetic interference.  Our research expertise includes optical fibre interferometry, polarimetry, fibre Bragg gratings, distributed feedback fibre lasers and microfibre sensors.  Optical fibre sensors can measure a wide range of measurands such as static and dynamic strain, temperature, pressure, acoustic and ultrasonic waves, electric and magnetic fields and can also be developed for chemical and biological sensing.