A joint research team led by Prof. JIN Wei, Associate Director of the Photonics Research Institute (PRI) and Chair Professor of Photonic Instrumentation in the Department of Electrical and Electronic Engineering, and Prof. WANG Yiding of Jilin University, have successfully developed a novel on-chip photothermal spectroscopy sensor for high-sensitivity gas detection.
Photothermal spectroscopy is an optical analysis technique which uses sensors to determine the composition of solids, liquids and gases. It works by exposing a sample to radiation and measuring the heat produced by the irradiated sample. Existing waveguide gas sensors have limited sensitivity and measurement range. The team demonstrated a new method which uses photothermal spectroscopy and an on-chip sensor to achieve gas measurement with high sensitivity.
The team developed a novel waveguide sensor which contains chalcogenide glass as the core-layer material. The sensor detects acetylene, a colourless flammable gas. The new sensing method achieved a remarkable acetylene detection sensitivity of 4 ppm and a dynamic range exceeding 5 orders of magnitude, outperforming the traditional direct absorption sensor.
Research findings have been published in Laser & Photonics Reviews (https://doi.org/10.1002/lpor.202301071). The team is now seeking to optimise the waveguide structure, improve thermal accumulation and more deeply understand the optical-thermal phase-transfer mechanism.
