Post-doctoral fellow in novel distributed sensing schemes over optical fiber networks - 24 months contract

Who we are ?

Télécom Paris, part of the IMT (Institut Mines-Télécom) and a founding member of the Institut Polytechnique de Paris, is one of France's top 5 general engineering schools.

The mainspring of Télécom Paris is to train, imagine and undertake to design digital models, technologies and solutions for a society and economy that respect people and their environment.

We are looking for a Post-doctoral Fellow in novel distributed sensing schemes over optical fiber networks. You will join the COMELEC Department in GTO team. The Optical Telecommunications Group (GTO) is home to the research programs of eight faculty members and a state-of-the-art laboratory on optical fiber transmission. We conduct advanced research in high-rate fiber-optic transmission, optical network architectures, novel lasers for communications, integrated photonics, and distributed optical fiber sensors

SCIENTIFIC CONTEXT

Context of the research project

Infrastructure monitoring relies on the collection and use of data extracted by many sensors delivering information on road traffic, detection of human presence and many events affecting the infrastructure (water and gas distribution networks, transports, etc.). The current approach to collect this information is to deploy a multitude of discrete and dedicated sensors. This deployment has a high logistical cost (installation, energy supply, maintenance). Urban DAS (Distributed Acoustic Sensing) using optical fiber is a new way to sense the environment. Telecom fiber optic networks already crisscross current cities: the use of this available infrastructure for the purposes of capturing, locating and identifying vibration events is a very attractive approach.

Characterization and localization of vibration events with the highest possible accuracy, followed by their identification using signal processing algorithms and artificial intelligence, paves the way for the provision of valuable data for a multitude of applications (road/rail traffic supervision, security, intrusion detection, seismic… ).

This project aims to benefit from the deployed optical transmission fiber cables as a multitude of passive sensors in order to make possible the telemetry (detection-localization-identification) of a set of vibratory phenomena. Its implementation however faces three major requirements: transparent integration (no impact on the quality of service of the telecom network), guarantee of an extreme sensitivity to vibratory phenomena affecting the fiber and post-processing to allow an optimal discrimination of the detected phenomena.

About the ANR 2024 SAFER project

SAFER for “Seamless Acoustic sensing over Fiber nEtwoRks” is a French project funded by the national research agency (ANR) through its generic call for proposals of 2024. It is coordinated by Élie Awwad from Télécom Paris and involves two partners: GTO team at Télécom Paris and Invisensing.io, a French start-up specialized in DAS products. SAFER is a four-year project that was launched in March 2025.

DAS approach relies on the existence of distributed Rayleigh backscattering, an inherent impairment in an optical fiber. The scientific barrier is mainly the low level of Rayleigh backscattering and its randomness. In an optical network, technical barriers also come from the heterogeneity of their topologies. For instance, the presence of multimode fibers in some legacy local area networks induce crosstalk among multiple propagating modes that might affect DAS sensitivity. In metropolitan networks, some optical devices can prevent the backscattering generated by the following fiber cables from reaching the interrogator (isolators, routing nodes…). In access networks, the existence of 1-to-N fiber topology (one fiber splitting to N through an optical splitter to serve N end-users) will lead to a localization ambiguity.  The resolution of these problems will be at the heart of this project. 

We propose to benefit from the deployed optical transmission infrastructure as a network of passive sensors to facilitate the telemetry of a large set of acoustic and vibratory phenomena reaching this infrastructure. Fiber is increasingly deployed in urban and rural areas, often throughout road and rail development projects. FTTx (Fiber To The x=Home, Building,…) networks and local area networks (LANs) are also developing fast, bringing the fiber closer to homes and workplaces to ensure the best quality of transmission and highest data throughput. The reuse of the optical infrastructure, whether through DAS or other sensing techniques, as a distributed vibration sensor, converts it into a neuralgic network enabling the detection of vibrations that propagate via different layers separating the vibration source from the fiber core.

We expect to deliver proof-of-concepts of novel sensing solutions that can address various sensing scenarios while targeting:

·       Zero impact on the quality of service (QoS) of the telecom network;

·       Achieving higher sensitivity levels, or wider scope of detectable strains than the state-of-the art and appropriate spatial resolutions for these scenarios.

·       Validating our solutions over lab setups and possibly field trials.

Our aim is to design cost-efficient vibration sensing schemes, including – but not limited to – DAS. The schemes should easily fit into the encountered topologies of deployed optical networks that include various fiber cable types and optical devices. Telecom operators are already discussing the introduction of sensing into telecom standards of ITU. First attempts in this direction are found in [6] for core and submarine networks where coherent receivers are used allowing for the extraction of phase and SOP from forward-propagating signals, yet with a very rough spatial resolution (several tens of km in). Besides, in terrestrial networks, optical isolators in optical amplifiers will filter out the backscattered signals preventing it from propagating between spans. We aim to design cost-efficient distributed sensing schemes that cope with the network constraints through two approaches:

1.       Integrating DAS function using minimum additional hardware and using telecom-grade components;

2.       Forward-propagation-based distributed sensing schemes with enhanced performance (spatial resolution and/or acoustic bandwidth).

Your main tasks will be to :

• To carry out research missions in the field of photonics

• To ensure supervision and tutoring missions

• To contribute to the reputation of the School, the Institut Mines-Télécom and the Institut Polytechnique de Paris

The ideal candidate will have a PhD or equivalent in electrical engineering, optical communications, photonics or related fields. Knowledge of optical transmission systems and networks is required. Knowledge of digital signal processing algorithms used in communication systems or fibre optic sensors is desirable. Skills in programming DSP algorithms (using MATLAB or Python) are appreciated.

You are known for your ability to work in a team and your interpersonal skills.

You have a professional level of English.

Why join us?
You'll be working in a fast-growing, pleasant, green and accessible environment (especially for people with disabilities) just 20 km from Paris (RER B and C suburban train lines, close to major roads, shared shuttle departing from Porte d'Orléans). You will benefit from :

• 49 days annual leave (CA + RTT)

• flexible working hours (depending on department activity)

• telecommuting 1 to 3 days/week possible

• 75% public transport pass reimbursement

• Proximity to numerous sports facilities, concierge service, underground parking, in-house catering, etc.

• Staff association at school and ministry level

• Good to know: our social security contributions are lower than in the private sector

Other information :
Application deadline: October 31, 2025
Job type : 24 months fixed-term contract

Foreseen starting date: February-March 2026
Job description here

Scientific contact person: Élie AWWAD  (elie.awwad@telecom-paris.fr)

Administrative contact person: Hamidou YAYA KONE (hamidou.kone@telecom-paris.fr)

Our recruitment is based on skills, without distinction of origin, age, gender identity, or sexual orientation, and all our positions are open to individuals with disabilities.