Postdoctoral position in Photonics

Duration : 2 years (24 month)

Starting date : September 2023

Location : Laboratoire Photonique, Numérique et Nanosciences (LP2N), UMR 5298, IOGS- CNRS-Université́ de Bordeaux, 33400 Talence, France

Employer : Institut d’Optique https://www.institutoptique.fr

Context

Spectroscopic techniques based on laser-matter interactions allow to probe the vibrational and magnetic degrees of freedom in solids by detecting the associated quantized quasi-particles namely phonons and magnons respectively. These methods rely on the inelastic interaction of light with the object of interest spectrally characterized by Stockes and antiStockes sidebands surrounding the light central wavelength. Current techniques are based on laser illumination with either continuous waves or femtosecond pulses. The most advanced commercially available femtosecond lasers deliver pulses at fixed repetition rates around 100 MHz and up to 1 GHz. On the other hand, the characteristic frequencies of phonons and magnons span from tens of GHz up to the THz level. Frequencies being so far apart, spectroscopy in this context remains limited to time-domain Brillouin scattering also referred to as coherent Brillouin scattering hence in a systematic out-ofresonance regime. In the framework of the GigaSpin project (funded by the ANR) we aim at building an instrument implementing a novel spectroscopy approach that relies on tunable optical resonant excitation where the laser repetitionrate can be continuously varied to match any magnonic or phononic eigen-frequencies of the material under investigation. In this context, we are currently developing a femtosecond laser system whose repetition rate is continuously tunable in the range of GHz up to the THz level.

Job description

The researcher will work within the GigaSpin team (5 people) at LP2N in close collaboration with a PhD student on the development of the ultrafast laser source. The topics covered include, but not limited to, fiber lasers and in particular Ybdoped fiber technologies, frequency combs and ultrashort pulses, non-linear propagation in fibers and waveguides, spectral and temporal optical shaping, advanced laser metrology and non-linear optics. She/he will also be involved in the experimental campaigns conducted in collaboration with our partners (IPR Rennes, Lab-Sticc Brest and UMPhy Palaiseau) aiming at characterizing the acoustic and magnetic properties of complex samples on the experimental resonant Brillouin spectroscopy platform driven by the GHz laser source at LP2N. Additionally, the researcher will actively participate to communication activities through peer-reviewed publications, topical meeting and conference presentations where she/he will promote her/his research.

Skills

The candidate must have a Ph.D in photonics, applied physics, optics or a related discipline. Advanced knowledge in fiber laser, non-linear optics, electro-optic modulation, optoelectronics or femtosecond technologies as well as proficiencies for numerical simulations are recommended. A fluent knowledge of English and/or French is a pre-requisite. The successful candidate will be highly motivated, creative, with demonstrated abilities to work in a collaborative environment.

References

[1] H. Ye et al., Opt. Express 28, 37209 (2020)

[2] O. Kovalenko et al., Phys. Rev. Lett. 110, 266602 (2013)

[3] L. Soumah et al., Nat. Commun. 9, 3355 (2018)