FRIPRO – FRINATEK Young Research Talents, The Research Council of Norway
Jana Jágerská/UiT Project Leader, April 2017- November 2022
First project, starting the field (and group) of mid-IR photonics for IR spectroscopy at UiT.
The primary objective of MICRO-Sense was to develop an integrated methane sensor of unprecedented sensitivity based on a photonic microchip with an innovative free-standing waveguide design optimized for maximum optical field interaction with the surrounding environment; The sensor was planned to be optimized for identification and quantification of methane emissions in the Arctic.
Key results
Within the project duration, two different types of photonic sensors were implemented, achieving exceptional sensitivity and selectivity for trace gas detection.
An original sensor design demonstrated in the project is based on free-standing thin film waveguides with rib core region. Supporting so-called free-space-like mode with largely extended evanescent field, these waveguides offer exceptionally high light-matter interaction with the surrounding gas and thus unprecedented sensitivity. We were the first to experimentally demonstrate that light-matter interaction of a guided mode in a carefully designed thin-film waveguide can exceed the light-matter interaction of a free-space beam, which is a fundamentally intriguing results that has attracted considerable attention of the research community. Published in a Nature family journal Light Sciences and Applications in 2021, this concept was further developed to realize a microstructred-cladding free-standing waveguide within the parallel sCENT project for both CO2 and CH4 detection.
Together with sCENT, the project also explored silicon-on-insulator slot waveguides optimized for the detection of methane. The sensor can detect methane with great selectivity at concentrations down to 300 ppb, which represents roughly a 1000-times improvement compared to state of the art represented e.g. by a sensor reported by IBM (Tombez et al., Optica 2017). Yet, oxide-supported slot waveguides cannot operate in the full mid-IR and their patterning is more demanding, making the free-standing geometries more attractive for practical use.
Although the ideas were conceived and the sensor chips were designed and fully tested at UiT, implementation of the waveguides was done in collaboration with the University of Southampton (Senthil G. Murugan) and NTNU (Astrid Aksnes).