Description du sujet de thèse

Awarded of the 2005 Nobel Prize in Physics, research on optical frequency combs has revolutionized the field of optics with the development of high-resolution spectroscopy for applications in healthcare, environment, security, and computing. However, frequency combs are still limited to niche applications today due to their difficult implementation. Very recently, the first demonstrations of frequency combs on a chip (microcombs) have paved the way for the future use of frequency combs in our daily lives: virus detection on a chip, autonomous sensors scanning air quality, not to mention industry, space, and defense.
In the OFCOC (Optical Frequency Combs On a Chip) project of the PEPR electronics program, we propose to create the first integrated, high-speed, robust, reliable, and miniaturized microcomb source on an entirely semiconductor platform. To do this, we are working on the co-integration of different photonic platforms such as mid-infrared laser emission platforms or nonlinear photonic platforms that can generate frequency combs using the Kerr effect.
In this context, in collaboration with C2N and INL, FOTON has developed GaP-based waveguides and photonic resonators with key advantages for the generation of Kerr frequency combs and their spectral translation by second-order nonlinear effects. However, the realization of complex photonic circuits with these advanced functionalities depends on the ability to reduce propagation losses within the GaP photonic platform below dB/cm. We have identified several technological avenues to explore in order to achieve this goal: obtaining sub-nanometer scale roughness, limiting material absorption, and passivation. As part of the thesis, the successful candidate will have the opportunity to explore different facets of photonic engineering, from the design and manufacture of photonic circuits to their optical characterization.
The candidates must have a master's degree or engineering degree, preferably with a background in semiconductor physics, solid-state physics, and photonics. They must have a keen interest in experimental work (clean room work, linear and nonlinear optics experiments), component design, and modeling of photonic phenomena.
Due to the multicultural work environment, fluency in English is required (written and spoken, level B2) and a good knowledge of French is desirable.

Contexte de travail

This thesis will be part of the OFCOC (Optical Frequency Combs on a Chip) project of the PEPR Electronics program. The OFCOC project brings together five partners at the national level and aims to develop the first integrated microcomb source in the mid-infrared (MIR) range. It therefore draws on the following areas of expertise:
- antimony-based ICLs (interband cascade lasers) manufactured at the IES in Montpellier,
- the GaP nonlinear platform developed at the FOTON institute (Rennes, GaP on native substrate and GaP/Si) and at C2N (Paris, GaP/GaAs),
- supercontinuum and comb generation in the MIR using the SiGe platform at INL (Lyon),
- frequency comb generation at telecom wavelengths on the SiNOI platform at CEA Leti (Grenoble).
This thesis will be hosted by the OHM team at the FOTON Institute, based at INSA Rennes, under the supervision of Yoan Léger and co-supervised by Cyril Paranthoën, INSA associate professor.

All applications must include the following:
• Cover letter
• Detailed CV
• Copy of master's degree or equivalent and marks
• List of publications, if applicable
• the contacts of 2 references

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The selected candidate will be required to work in a clean room environment (chemical hazards) and in a photonic characterization laboratory (exposure to laser radiation).