CEA-Leti Researchers Achieve Breakthrough in Miniature Quantum Cascade Lasers for Medical Sensing

For over a decade, CEA-Leti has been exploring the potential of quantum cascade lasers (QCLs) across various applications. Recent research presented at SPIE Photonics West in January marks a significant advance: the successful integration of QCLs with silicon photonic platforms for mid-infrared (MIR) applications.

A key breakthrough emerged from the institute’s Optical Sensors Lab, where a team has developed a method to integrate high-performance mid-infrared QCL sources directly onto silicon wafers using heterogeneous III‑V‑on‑Si bonding. This technique creates a scalable, low-cost platform for producing compact, powerful optical sensors suitable for everyday use—particularly in the continuous monitoring of chronic diseases.

Badhise Ben Bakir, research engineer and QCL theme leader, explained the significance: these lasers operate in the mid-infrared range, where molecules exhibit distinct absorption fingerprints, enabling highly specific chemical detection.

To overcome integration challenges, the ten-person team will fabricate micro-laser sources in CEA-Leti’s cleanrooms, leveraging advanced microelectronics technologies. Badhise emphasized that the “smart” integration of III‑V materials on silicon is a breakthrough that unlocks new design possibilities.

Looking ahead, research engineer Maëva Doron highlighted that transitioning complete QCL systems from the lab to practical sensors requires multidisciplinary expertise in design, modeling, manufacturing, characterization, and packaging. The work involves collaboration across roles, including process integration led by Marion Volpert and optical sensor development by Doron herself, under the thematic leadership of Badhise Ben Bakir.

This integration breakthrough paves the way for miniaturized, affordable MIR sensors that could revolutionize non-invasive health monitoring and environmental sensing.

​For more than10years, CEA-Leti researchers have investigated the contributions that quantum cascade lasers (QCLs) can offer across a wide spectrum of fields and applications.In January, the institute presented new research atSPIE PhotonicsWest highlighting major progress in the integration ofQCLswith silicon photonic platforms for mid-infrared (MIR) applications.​​

Meanwhile, in the Optical Sensors Lab of the Optics and Photonics Department, a research team achieved a QCL engineering breakthrough that could dramatically reshape continuous monitoring of chronic diseases. By integrating high‑performance mid‑infrared QCL sources onto silicon wafers through heterogeneous III‑V‑on‑Si bonding, they created a scalable, low‑cost platform capable of delivering compact, powerful optical sensors for everyday use.

Badhise Ben Bakir, research engineer-QCL theme leader, noted that these lasers emit in the mid-infrared range, where molecules have a true absorption fingerprint.

To address these challenges, the 10-person team will develop micro-laser sources in CEA-Leti's cleanrooms, which use advanced microelectronics technologies.

Badhise, who said the “smart" integration of III-V on silicon was a breakthrough, added that this integration approach also opens new design possibilities:

Looking head toward the wide spectrum of R&D possibilities, Maëva Doron, research engineer-optical sensors, said bringing complete QCL systems from the lab to everyday sensors requires key expertise in design and modeling, manufacturing, characterization and packaging.

​​Marion Volpert, research engineer-process integration

Maëva Doron, research engineer-optical sensors

Badhise Ben Bakir, research engineer and QCL theme leader