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CEA-Leti innovates in chemicals sensing with photo-acoustic solutions

Published on 14 April 2023


   What is µPAsense?

  • The photoacoustic spectroscopy technique is based on the absorption of light by the molecules of interest and the subsequent generation of acoustic waves. This technique, typically used for high-resolution mid-IR spectroscopy, is today confined to laboratory applications due to its size and cost. Leti proposes μPAsense, a compact photoacoustic sensor working in the mid-infrared region, by assembling a multi-wavelength quantum cascade laser (QCL) source with a photonics integrated circuit (PIC) combiner in a small photoacoustic cell (a few cm3). This sensor allows multigas detection with very high sensitivity down to a few ppb level.


Trace gas detection and sensing in:
  • Environmental
  • Process control
  • Quality assurance
  • Safety & security
  • Early disease diagnosis

   What's new?

CEA-Leti's teams are focusing on miniaturization of the sensor at chip or packaging level to address cost reduction, multigas detection and portability.

Key achievements toward miniaturization are:
  • The effective fabrication process for QCL sources (originally developed by our startup partner mirSense): the wavelength of each laser is selected independently after the growth of the epitaxial layers
  • Low-loss waveguides based on Ge and SiGe alloy to realize the PIC combiner (losses as low as <1dB/cm on the 3-12 μm range)
  • Mini acoustic Helmholtz detectors fabricated on silicon and based on MEMS microphones suitable for trace-gas detection

mirSense, a CEA-Leti's startup company, is currently industrializing and commercializing this mini photoacoustic gas sensor.

  What's next?

CEA-Leti currently is working on:
  • Transfer of the QCL fabrication process on silicon wafer
  • Realization of the photoacoustic detector on silicon
  • New designs of the photoacoustic cell to improve resolution and stability
  • Ozone detection in the UV band


 10 patents on photoacoustics & sensor integration

 11 publications (2013-2019)

 Partnership with mirSense
company since 2015


 Multigas sensors from one to tens of species (with absorption lines in the 3-12 μm wavelength range)

 Ultra-low limit of detection down to few ppb

 Portable system, low volume

 Highly selective identification

 Real-time measurement
  •       FLYER

    (201 Ko)