Faites connaître cette offre !
Reference : UMR7341-OLIUTE-002
Workplace : MARSEILLE 09
Date of publication : Tuesday, June 16, 2020
Scientific Responsible name : Olivier Utéza and Marc Sentis
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2020
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Damage to solid targets by ultra-short laser pulses critically raises the problem of the fragility of optical components, particularly those incorporating metallic structures that allow them to have an achromatic highly-reflective capability over a very wide spectral range. This fragility is, for example, a key point in the operation of ultra-short power laser sources (femtosecond PW lasers), and to access relativistic optics and its applications (particle acceleration, quantum electrodynamics, microphotonics and relativistic microelectronics). Moreover, when the peak laser power is lower, femtosecond laser sources are able to induce remote, localized and volume/surface interactions in most materials. The extreme agility of these lasers is thus a source of important advances, particularly for applications such as the local structuring of materials to give them a specific function (optics/photonics, tribology, etc.).
In the context of a first Ph'D funding (2016-2019), we have been able to demonstrate that the damage of a dielectric material in ultrashort regime is facilitated (reduction of the damage threshold fluence) compared to longer pulse durations. We have also shown that reducing the pulse duration to a few optical cycles (10-15 fs) does not induce any particular enhanced vulnerability in the case of metallic targets.
These results, original at such pulse durations, may seem surprising or contradictory and the core of the work proposed in this Ph'D thesis will be positioned in a double perspective, fundamental and applied. The aim will be to gain a detailed understanding of laser heating in the ultra-short regime, particularly in the case of transition (e.g. tungsten, nickel) and post-transition (aluminum) metallic materials, and then to apply this knowledge to develop smart irradiation strategies (multi-spectral, multi-pulse) making it possible to reduce (or increase) the energy dose necessary for material damage or structuring.
Understanding and shaping the transformation of a material in an agile and energy-efficient manner as allowed by an ultra-short laser pulse will therefore promote the emergence of a key technology for the development of intelligent functionalized materials and propose solutions to reduce the vulnerability of optical components. The subject of this thesis work thus addresses two themes that are currently undergoing strong expansion and vitality, Photonics and Materials.
The LP3 laboratory is composed of about thirty people, and it is a joint research unit (UMR 7341) of CNRS (http://www.cnrs.fr/) and University of Aix-Marseille (https://www.univ-amu.fr/). LP3 is located on the Luminy campus, at the gateway to the Parc national des Calanques.
The laboratory's scientific activity is focused on laser-matter interaction in short and ultra-short pulse regimes. The research carried out concerns the understanding of the fundamental phenomena governing the interaction between a pulsed laser beam and matter and the development of innovative photonic processes issued from this knowledge.
To carry out the Ph'D thesis works, the student will use the ASUR laser system (Platform for Applications of Ultra-Fast Sources) and benefit from a favorable environment within the laboratory (diversity of laser sources and characterization tool and analysis: AFM, SEM, optical, confocal and Raman microscope, spectrometer, etc.). His/her works will be done in the context of a small research group of about 5 people working on the theme of laser-matter interaction in ultra-short regime (including the 2 co-supervisors of the thesis: M. Sentis and O. Utéza). For information, ASUR is a multibeam installation with a wide range of characteristics (10/20 TW @ 25 fs - 8 GW @ 15fs, 800 nm, nominal 25 fs, output < 15 fs available, OPA fs: UV - IR) on which pump-probe experiments have already been developed in previous Ph'D theses.
Constraints and risks
The person recruited will be of European or Swiss nationality (mandatory in the context of the funding) and he/she have received a solid training in Optics, Lasers and Materials Physics. He/she will hold a Master 2 (or equivalent) in Physics. He/she will have good experimental work skills as well as good oral and written communication skills to present his/her work in seminars and conferences and to write scientific papers and articles (good level in English required and French language appreciated, however not mandatory).
Applications should include a detailed CV, a letter of motivation, letters of reference if possible, transcripts of the two years of Master's and Bachelor's (or engineering school) degrees.
Deadline for application: 31 August
We talk about it on Twitter!