REDFINCH yields prototype portable photo-acoustic sensor for gas detection and analysis

Grenoble-based micro- & nanotechnology R&D center CEA-Leti has announced the development of a prototype miniaturized, portable optical sensor for the chemical detection of gas – the subject of an invited paper ‘Photo-acoustic cell on silicon for mid-infrared QCL-based spectroscopic analysis’ (which won Best Paper Award at Photonics West 2019).

The next-generation centimeter-size photo-acoustic sensors are based on mid-infrared photonic integrated circuits (MIR PICs). The silicon PICs, created by integrating optical circuits onto millimeter-size silicon chips, comprise extremely robust miniature systems, in which discrete components are replaced by on-chip equivalents, making them easier to use and reducing their cost dramatically (by at least a factor of 10, it is expected).

Developed by the European Commission’s REDFINCH project (headed by CEA-Leti), the prototype photo-acoustic sensors were fabricated on a CMOS line in a miniaturized silicon photo-acoustic cell, allowing extreme integration.

In demonstrations, the sensors match the performance of bulky commercial gas-sensing systems commonly available now. They are targeted at applications such as process gas analysis in refineries, gas leak detection in petrochemical plants and pipelines, and protein analysis in liquids for the dairy industry.

The sensors aims to consume less than 10W in continuous operation. They can be operated in a slow pulse-burst mode for infrastructure monitoring and, when leaks are detected, the pulse frequency of the sensor automatically increases. This keeps average power consumption very low, so the sensors can be battery-operated for more than a year or powered by an ambient energy harvester (e.g. a solar cell).

“The big picture is that the miniaturization of photo-acoustic spectroscopy based on quantum cascade lasers (QCLs) is entering the stage of mass production,” says Jean-Guillaume Coutard, an instrumentation engineer at Leti who coordinate the project.

To develop the chemical sensors, the REDFINCH consortium overcame the challenge of implementing their capabilities in the important mid-infrared region, where many important chemical and biological species have strong absorption fingerprints.

“This allows both the detection and concentration measurement of a wide range of gases, liquids and biomolecules,” says Coutard. “This is crucial for applications such as health monitoring and diagnosis, detection of biological compounds and monitoring of toxic gases,” he adds.

“This project is a perfect fit for mirSense’s development roadmap,” says Mathieu Carras, CEO of mirSense, which participated in the project. “Our mission is to democratize QCL usage,” he adds. “mirSense is ready to produce these state-of-the-art integrated QCL-based components and do a similar job on electronics and software to bring the value of this technology to the market.”

The consortium members and contributions include:

Cork Institute of Technology (Ireland) – PIC design & fabrication, hybrid integration;
Université de Montpellier (France) – laser growth on silicon, photodetector growth;
Technische Universität Wien (Austria) – liquid spectroscopy, assembly/test of sensors;
mirSense (France) – MIR sensor products, laser module integration;
Argotech a.s. (Czech Republic) – assembly/packaging of PICs;
Fraunhofer IPM (Germany) – gas spectroscopy, instrument design/assembly;
Endress+Hauser (Germany) – process gas analysis and expertise, testing validation.

See related items:

Leti-led EU project REDFINCH to develop PIC-based mid-IR portable sensors for chemical detection in gases and liquids

Tags: Leti Mid-infrared detectors PIC

Visit: www.redfinch.eu

Visit: www.leti.fr