Post-doctoral position : Photonic circuit for light pulse compression (M/F)

Job Description

Missions

Mid-infrared spectroscopy is a virtually universal method for identifying chemical and biological substances and performing non-intrusive diagnostics. Indeed, within the 6 to 15 µm wavelength range, most molecules exhibit vibrational and rotational resonances at very specific wavelengths. This wavelength range can therefore be exploited to detect traces of toxic and environmentally hazardous substances. A current challenge lies in making mid-infrared spectroscopy widely accessible by fostering the development of compact, cost-effective solutions. This postdoctoral position is part of the EU-funded UNISON project, which aims to demonstrate a highly scalable, cost-effective, and compact platform for infrared spectroscopy. The groundbreaking technology involves a compact, low-cost integrated spectrometer that covers the entire mid-infrared spectral range (wavelengths from 3 to 12 µm) and is capable of fitting into the limited space of an Internet of Things (IoT) device. To achieve this goal, UNISON will utilize electrically pumped cascade lasers (QCLs and ICLs) and mid-IR silicon-germanium (SiGe) photonic circuits. Beyond the physical and technological challenges associated with the project's specific objectives, integrating QCLs or ICLs with SiGe photonic circuits represents a major challenge.

Activity

The objective of this postdoctoral project is the generation of optical pulses using QCL frequency combs. Pulse generation will be implemented on SiGe integrated circuits developed at C2N. Building upon an initial demonstration involving C2N and ETH (https://doi.org/10.1002/lpor.202501485), this project aims to advance the approach by demonstrating the generation of high-power, ultrashort pulses (sub-picosecond). The key challenges to be addressed are: - Chirp management within SiGe integrated circuits across a wide optical bandwidth - Reduction of optical losses (coupling and propagation).

Your Profil

Skills

We are seeking a candidate with experience in integrated optics—ideally in the mid-infrared spectral range, though this is not a strict requirement. Ideally, the candidate should have experience in simulation, cleanroom fabrication, and optical characterization. Furthermore, the candidate will work on a European Pathfinder project (2024–2028)—launched in March 2024 and involving seven international partners—with C2N acting as the project coordinator. A high level of involvement in the project is expected (presenting at project meetings, contributing to deliverables, participating in management tasks, etc.). The ability to communicate and share results within a multidisciplinary and multinational environment is strongly expected.

Your Work Environment

The Center for Nanoscience and Nanotechnology (C2N) is a joint research unit of the CNRS, Université Paris-Saclay, and Université Paris Cité, located in Palaiseau, near Paris. The laboratory conducts world-renowned research projects in the fields of photonics, materials science, nanoelectronics, microsystems, and nanofluidics. C2N has a staff of nearly 400 and houses one of the largest university-based nanotechnology facilities in France, with a 2,900 m² cleanroom. Within C2N, the Silicon Photonics group (https://minaphot.c2n.universite-paris-saclay.fr/en/) has extensive expertise in passive and active photonic devices based on silicon, silicon nitride, and germanium. The group is at the forefront of photonics research, with several pioneering demonstrations of optoelectronic devices, including optical modulators, photodetectors, passive devices, metamaterials, and metasurfaces. The group has access to several optical setups for the active and passive characterization of photonic devices from 600 nm to 16 μm wavelengths. The research group's main anticipated applications are optical telecommunications/interconnects, microwave photonics, biochemical and gaseous detection, spectroscopy, and data communications. This position offers the opportunity to work within an enthusiastic and international team in the exceptional environment of C2N. We provide access to state-of-the-art fabrication infrastructure and characterization laboratories, with the opportunity to propose and explore new research ideas. The position is located in a sector related to the protection of scientific and technical potential (PPST), and therefore requires, in accordance with regulations, that your arrival be authorized by the competent authority of the MESR.

Compensation and benefits

Compensation

3131 à 4341 € gross monthly, depending on experience

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions