A silicon photonics based terahertz gas sensor

01 January 2018 → 31 March 2022
Research Foundation - Flanders (FWO)
Research disciplines
No data available
terahertz gas sensor
Project description

As our world becomes more complex and the effects of human activities on the environment and their own health increases, the need to map and understand what we expel into our surroundings grows. Especially gases, which are often color- and odorless, often have big implications on the health of humans and the planet as a whole. Having a sensor that is both cheap and small enough to be used ubiquitously would enable us to measure and understand the influences of human actions. This project aims to build such a cheap, chip-scale, sensitive gas sensor. The size and price are kept low by employing silicon photonics. The sensitivity will be ensured by using photoacoustic spectroscopy. Furthermore we operate in the terahertz frequency range which typically interacts with gaseous molecules of many different species in a highly selective manner due to the typically rotational nature of the excitations. This gives us an advantage over infrared spectroscopy which is concerned with vibrational modes and hence is unsuited to discriminate between isomeres.
In photoacoustics a gas is modularly heated when it interacts with light (an effect inherent to terahertz excitations), creating a pressure wave. This waves hits a mechanical resonator whose frequency matches that of the soundwave and its movement forms the signal. We will improve this technique by achieving better light concentrations and having an optical, acoustical and mechanical resonator in one system.