Description du sujet de thèse

Awarded the Nobel Prize in Physics in 2005, work on optical frequency combs has revolutionized the field of optics, with the boom in high-resolution spectroscopy for health, the environment, security and information technology. However, frequency combs are still limited to niche applications, as they are difficult to implement. Very recently, the first demonstrations of frequency combs on chip (microcombs) have opened the way to the volume use of these frequency combs.

Challenges / objectives of the internship
As part of the OFCOC (Optical Frequency Combs On a Chip) project of PEPR électronique, we are proposing to develop the first integrated, broadband (visible to mid-infrared), robust, reliable and miniaturized microcomb source.
This will be based on the remarkable non-linear properties of GaP (in partnership with FOTON and C2N) and Silicon germanium (in partnership with CEA-LETI) at these high wavelengths, and the exploitation of parametric processes to generate light over a very wide spectral band (covering the 3-13 um range). The aim is to develop i) sources tunable over a wide spectral band (based on wavelength conversion) ii) "supercontinuums" and iii) multispectral sources or "COMBs". The PhD student will be involved in all stages of the project, from device design (FEMSIM, FDTD, nonlinear Schrodinger electromagnetic modeling tools), device fabrication using cleanroom processes via INL's NANOLYON nanotechnology platform (nanolithography, etching, micro-transfer printing, etc.), to linear and nonlinear optical characterization.
The work will be presented at prestigious international conferences and published in high-impact journals.

Scientific supervision and collaborations
The PhD student will work under the supervision of Christian Grillet and Prof. Christelle Monat in the iLUM team at the Institut des Nanotechnologies de Lyon (INL- UMR 5270) as part of the PEPR e- OFCOC (Optical Frequency Comb On a Chip) project.
He/she will contribute to the development of integrated nonlinear functions such as combs and mid-infrared supercontinuum sources on Ge/SiGe and SiN platforms (in collaboration with CEA-LETI), GaP (in collaboration with FOTON and C2N).
He/she will be involved in all stages of the project, from device design using commercial electromagnetic modeling tools (MODE or FDTD from LUMERICAL, RSOFT...) or developed in-house (nonlinear equations from Schroedinger, LLE...) to device fabrication using cleanroom processes via the NANOLYON nanotechnology platform (nanolithography, etching, microtransfer printing... ) and their optical characterization (on a complete optical bench - edge coupling, micro-reflectivity, Fourier optics, non-linear characterization, pulsed laser, parametric processes - which the student will have helped to design and deploy) and data processing.

Contexte de travail

The candidate should have a solid background in physics and optics (nonlinear optics would be a plus), with a strong taste for manufacturing, experimental and characterization aspects.
The candidate should have excellent written and oral skills (French if possible and English).
We're looking for a young researcher who is committed to the project, curious, autonomous and highly motivated to develop skills that go beyond purely nonlinear optics (application of combs for spectroscopy, metrology, telecom, etc.).
Applications should include a detailed CV; at least two references (people likely to be contacted); a one-page cover letter; a one-page summary of the Master's thesis; grades from Master 1 or 2 or engineering school).

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 successful candidate shall be enrolled on a PhD programme of the EEA doctoral school. Short trips in France (to our PEPR collaborators) and abroad (Australia) are to be expected.