Miniaturized gas sensors based on Mid-IR spectroscopy
In a H2020-project MIREGAS, Technical Research Centre of Finland VTT Ltd and Tampere University of Technology teams, together with European partners, developed novel components for miniaturized gas sensors exploiting the principle of Mid-IR absorption spectroscopy. In particular, the main advances concerned the development of novel superluminescent LEDs for 2.65 µm wavelength, Photonic Integrated Circuits (PICs) with 1nm bandwidth for spectral filtering at Mid-IR, hot-embossed Mid-IR lenses for beam forming and photodetectors for 2 to 3µm wavelengths. Silicon photonics PIC technology that was originally developed for optical communication applications allows for the miniaturization of the sensor. The components entail important benefits in terms of cost, volume production and reliability .
The market impact is expected to be disruptive, since the devices currently on the market are typically complicated, expensive and heavy instruments. The components developed by the consortium enable miniaturized integrated sensors with important benefits in terms of cost, volume production and reliability, which are instrumental features for the wide penetration of gas sensing applications .
The IR spectroscopy is a powerful tool for multigas analysis. Conventional sensors are based on the use of filters, spectrometers or tuneable lasers. MIREGAS project, has introduced breakthrough components, which enable multigas analysis using integrated solution. Moreover, using the new technology, the wavelengths of light can be filtered more precisely, and interfering gas components can be excluded.
H2020 European consortium, MIREGAS, brought together world-leading European institutes and multinational companies. On the technology side, VTT Technical Research Centre of Finland Ltd coordinated the programme and provided Si PICs as well as photonics packaging and integration technologies. The Optoelectronics Research Centre at the Tampere University of Technology in Finland was responsible for developing innovative superluminescent LEDs, ITME (PL) for mouldable Mid-IR lenses and VIGO (PL) for Mid-IR detectors. Industrial partners Vaisala (FI), AirOptic (PL) and GasSecure (NO) brought their competences in the areas of gas sensing and Mid-IR sensor fabrication, and at the same time, validated the technologies developed by the consortium.
“The project will enable us to extend our gas sensing technology into new market areas. The MIREGAS technology offers a unique mix of sensitivity, selectivity and competitive pricing that will be a complement to our present high-performance, laser-based sensing technology. Airoptic plans to a release a first product for hydrocarbon detection based on the technology developed within the MIREGAS project in 2019”, says CEO Pawel Kluczynski from Airoptic.
"Bearing in mind the potential market for devices developed in the MIREGAS project, VIGO System SA has started to implement a development plan that assumes investments in increasing technological and production capacities - which will allow for the future, high volume production of sensors based on SLED sources. The main actions of the plan are the purchase of a high-performance epitaxial machine, the expansion of the assembly capabilities and the acquisition of specialists in the field of epitaxial materials for the production of IR sources," stated Chief Sales Officer Przemysław Kalinowski from VIGO.
“Within this project, ITME was able to establish technology for low-cost mid IR optics development using moulding optics approach. We have developed several novel glasses transparent from visible up to Mid-IR range. We establish moulding processing that allow us to develop free-form optical components with optical surface quality for Mid-IR without further polishing. It allows to reduce cost of production first, but also to develop lenses in environment friendly matter since number of glass waste is dramatically reduces. Also grinding and polishing process that requires use of large amount of water and polishing powders is totally redundant. We found also new materials for mould development that are low cost and can be processed with standard CNC machines. This way our technology becomes cost effective also for prototyping and short series of components. This breakthrough give access for custom made free-form glass optics even for SME companies,“ says Prof. Ryszard Buczynski, head of Department of Glass, ITME. “Now we verify market potential of our technology and offer access to this technology as a custom service through ITME. After market validation, we plan to transfer this technology to other existing companies or establish spin-off company. Some venture funds and world-recognized companies already expresses their interest in our innovations.”
“At the start of the project, Mid-IR SLED technology targeting high-brightness and broadband operation was simply not existing. MIREGAS enabled important scientific breakthrough; in fact, the project results represent the state-of-the-art both in terms of power and wavelength coverage. Yet, what it is maybe the most important, contributed to creating a new European ecosystem based on combined expertise in Mid-IR optoelectronics and Si-photonics. We are just at the start of many other applications we will target with this powerful combination of technologies”, adds Prof. Mircea Guina, the head of ORC team at Tampere University.
“VTT’s Silicon-on-Insulator (SOI) based Photonic Integrated Circuit (PIC) technology owns two unique features: Firstly, in addition to the conventional optical communications wavelengths at 1550 nm, it is applicable for Mid-IR wavelengths; Secondly, it allows for the integration of active devices, such as, laser diodes or photodetectors, directly on the PIC chip. Therefore, the SOI PIC technology is very attractive for gas sensing and sensor integration, in general. In the MIREGAS project, we were able to take this offering to the next level together with the beneficiaries”, stated Pentti Karioja, VTT, project coordinator.
