Leti, a research institute of CEA Tech, today announced the launch of the REDFINCH consortium to develop the next generation of miniaturized, portable optical sensors for chemical detection in both gases and liquids. Initial target applications are in the petrochemical and dairy industries.

The consortium of eight European research institutes and companies will focus on developing novel, high-performance, cost-effective chemical sensors, based on mid-infrared photonic integrated circuits (MIR PICs). Silicon PICs — integrating optical circuits onto millimeter-size silicon chips — create extremely robust miniature systems, in which discrete components are replaced by on-chip equivalents. This makes them easier to use and reduces their cost dramatically, expected at least by a factor of 10.

To develop these chemical sensors, the consortium must overcome the significant challenge of implementing these capabilities in the important mid-infrared region (2-20 μm wavelength range), 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, which is crucial for applications such as health monitoring and diagnosis, detection of biological compounds and monitoring of toxic gases.

Initially, REDFINCH will focus on three specific applications:

• Process gas analysis in refineries
• Gas leak detection in petrochemical plants and pipelines
• Protein analysis in liquids for the dairy industry.

Silicon photonics leverages the advantages of high-performance CMOS technology, providing low-cost mass manufacturing, high-fidelity reproduction of designs and access to high-refractive index contrasts that enable high-performance nanophotonics.

“Despite the mid-infrared wavelength region’s importance for a wide range of applications, current state-of-the-art sensing systems in the MIR tend to be large and delicate. This significantly limits their spreading in real-world applications,” said Jean-Guillaume Coutard, an instrumentation engineer at Leti, which is coordinating the project. “By harnessing the power of photonic integrated circuits, using hybrid and monolithic integration of III-V diode and interband cascade and quantum cascade materials with silicon, the consortium will create high-performance, cost-effective sensors for a number of industries.” 

In addition to Leti, whose expertise includes the design and manufacture of PICs on a 200mm pilot line and integrated photoacoustic cells on silicon, the consortium members and contributions include:

• Cork Institute of Technology (Ireland) – PIC design & fabrication, hybrid integration
• Université de Montpellier (France) – Laser growth on Si, 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.