Job offer

European Commission; France; Sur place; EUR 35 000 - 52 000; Plein temps

Résumé du poste

Un poste de chercheur est proposé au sein d'un projet collaboratif sur les télécommunications optiques en environnement complexe. Vous travaillerez sur la modélisation et l'évaluation des performances des systèmes de télécommunication, analystes les impacts des conditions atmosphériques. Ce rôle requiert une solide formation en optique et expérience en programmation, avec un engagement vers l'innovation dans ce domaine en pleine expansion.

Qualifications

• Ingénieur ou Master 2 avec une spécialisation en physique/optique ou mathématiques appliquées.
• Ph.D. requis en optique ou mathématiques appliquées.
• Compétences en modélisation physique et programmation nécessaires.

Responsabilités

• Modéliser la propagation des ondes optiques dans des atmosphères complexes.
• Évaluer les performances de techniques de filtrage de photons.
• Définir les spécifications technologiques pour des dispositifs optiques.

Connaissances

Modélisation physique

Programmation

Statistiques

Formation

PhD en optique, mathématiques appliquées ou traitement de l'information

Outils

Matlab

Python

Description du poste

Organisation/Company CNRS Department Institut Fresnel Research Field Engineering Physics Technology Researcher Profile Recognised Researcher (R2) Country France Application Deadline 25 Jun 2025 - 23:59 (UTC) Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Sep 2025 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Description of the job :
In the applicative context of free space optical telecommunications (FSOT) (see project summary below),
you will be involved in the physical and numerical modeling of optical wave propagation through
complex and turbid atmosphere, and in the performance assessment of balisting photons filtering
approaches in the SWIR and MWIR wavelength ranges. Using realistic applicative scenarii, and medium
characteristics (size distribution of scatterers, type of scatterers, spectroscopic properties, dynamical
properties...), the absorption, scattering and depolarization properties of the medium will be simulated,
relying on analytical models and validated through numerical simulations (vectorial Radiative Transfer
Equation solved with Monte-Carlo simulations). The impact of propagation of light through turbid
atmosphere on the (classical or chaos-based) temporal modulation waveforms encoded onto the light
beam will be also analyzed with similar modeling tools, taking into account the geometrical
characteristics of the telecommunication system (e.g., aperture of the detection device) : this study
should provide an estimate of the maximal range and bandwidth of FSOT as a function of the fog
properties.
Then, you will be in charge of a theoretical and numerical evaluation of the benefits of
ballistic/serpentile photons filtering approaches (polarization or temporal-modulation based) on the
quality of FSOT in the SWIR/MWIR. Relying on the simulation building blocks set up, you will simulate
the implementation of such a serpentile/ballistic photon filtering technique by temporal modulation of
intensity and/or polarization, and analyze the potential gain in telecommunication performance. As far
as possible, these numerical approaches will be backed up by analytical studies of possible performance
gains in modulated signal discrimination, using the tools of statistical information theory. Finally, you
will handle the definition of technological specifications for the design of appropriate optical
phase/polarization modulation devices in the SWIR/MWIR ranges to implement ballistic photons
filtering for FSOT and increase the range and throughput of free-space optical telecommunication
systems in the presence of fog.

Public summary of the collaborative project :
Free-space optical telecommunications (FSOT) in the infrared represent an increasingly attractive alternative to the progressive
saturation of channels dedicated to wireless technologies, and to the growing bandwidth requirements. However, this
promising, rapidly deployable technology is vulnerable to weather conditions such as fog. Indeed, when the optical beam
propagates through a scattering medium, it undergoes absorption and scattering phenomena that attenuate the optical signal
and, at high data rates, cause time elongation of modulation signals. The greater the transmission distance, the greater these
effects, endeavouring communication reliability or bandwidth. In addition, the multiple scattering of the beam means that the
signal can be intercepted by an opposing party at a suitable distance. Securing transmitted data and increasing the range of
encrypted telecommunication systems through turbid environments such as fog is therefore a fundamental challenge for
defense and industrial applications.
The aim of this collaborative project is to propose new telecommunication strategies to significantly increase the range and
throughput of free-space optical telecommunication systems in the presence of fog. Data security will be achieved using a
cryptographic method that exploits the temporal chaos of quantum cascade laser sources. The proposed strategy involves the
combination of three innovative approaches : (i) chaos-based cryptographic encoding ; (ii) ballistic/serpentile photons filtering ;
(iii) wavefront correction through adaptive optics techniques to correct for the effects of scattering. One of OPTOPIRAT's
objectives will also be to compare telecommunication performance at different wavelengths, moving from the near infrared
(SWIR) to mid-infrared (MWIR, LWIR), while covering the main fog conditions (advective and convective).

Training requirements : Engineering school and/or Master 2 with a major in physics/optics
and/or applied mathematics. PhD in optics, applied mathematics, or signal/information processing.
Experience & skills : Good skills in optics, physical modeling and programming are required.
An appetite for statistics and signal/information processing will be appreciated.
Programming : Matlab, Python.