PhD Position - Advanced fiber Bragg grating sensors

B-PHOT is looking for a PhD candidate in Photonics/Electrical engineering: femtosecond laser-inscribed advanced fiber Bragg grating sensors for laser dynamics aided crack detection.

Optical fiber-based sensing stands as a cornerstone measurement and detection technology across diverse fields and disciplines, showcasing remarkable efficacy in applications ranging from structural health monitoring in civil engineering to biomedical sensing in healthcare. The detection of ultrasonic guided waves using optical fibers, which could be key enabling for structural health monitoring of aerospace structures, has so far remained out of reach. A breakthrough in terms of sensitivity and detection speed is required. To address this, we have already explored and successfully demonstrated fiber sensing by ways of laser dynamics. Owing to the fast response time and high-sensitivity of the laser itself, we believe that this approach holds potential for significant advancements in fiber sensor interrogation. However, such a sensing scheme requires fiber gratings with customized refractive index modification profiles that are specially designed and fabricated in fibers to enhance the sensitivity of the laser dynamics.

We have recently won a grant for the project named LADYBIRD, funded by the Research Foundation of Flanders (Fonds Wetenschappelijk Onderzoek, FWO). The aim is to experiment with and investigate the relevance of laser dynamics-based approaches for fiber sensing and apply the technique to the detection of ultrasonic guided waves. Within the project we target developing our own approach for grating-based sensor fabrication. This will be done by means of inverse grating design and plane-by-plane femtosecond laser inscription approach, which allows reaching unprecedented control over amplitude and phase response of the gratings. In this context, we are looking for an excellent PhD candidate in photonics (duration = 48 months) to join our team.

The research work will include:

• Development of inverse design approach for periodic and aperiodic fiber Bragg gratings with target amplitude and phase response.
• Mastering fabrication and characterization of custom fiber Bragg gratings with advanced spectral response profiles using the state-of-the-are femtosecond laser micromachining setup at B-PHOT Photonic Innovation Center.
• Implementation of plane-by-plane grating inscription approach in standard and specialty fibers, such as photonic crystal fibers, multi-core optical fibers, and few-moded fibers.
• The construction of an experimental setup for the precise generation and detection of ultrasonic guided waves with fiber Bragg grating sensors.
• Collaboration with a second doctoral researchers to optimize the architecture of fiber grating interrogation and sensing, fostering synergistic innovation and breakthrough advancements.

The candidate will join the Brussels Photonics (B-PHOT) research group of the Vrije Universiteit Brussel (VUB) in Belgium, www.b-phot.org. Chaired by Prof. Hugo Thienpont, the team composed of more than 45 internationally recognized researchers is widely known for its work in fundamental and applied photonics research covering the entire research cycle from modelling and fabrication, to characterization and Proof-Of-Concept. In the last 20 years, the group has built significant expertise in the field of optical fiber sensing applied to real-life and industrial applications, and in the field of semiconductor laser – including modelling, design and on-chip implementation of new laser structures – but also in nonlinear dynamics and chaos-based applications. The candidate will therefore have the opportunity to contribute to these fields in a multidisciplinary setting.

Starting date: September – December 2024.

• Candidates should possess a master’s degree in Electrical Engineering, Physics, Photonics, Applied Math or related scientific field. Interest in photonic system and light technology are necessary.
• Knowledge about optical fibers, fiber Bragg gratings, fiber grating inscription, femtosecond laser machining and fiber sensing is a strong plus.
• Good knowledge of numerical techniques and advanced simulation methods (Lumerical FDTD and MODE, COMSOL) is a plus.
• Experience with experimental optical setup, fiber optics and equipment such as optical fiber interrogators, optical spectrum analysers, photodetectors or high-precision positioning and motion systems is a plus.
• Knowledge about photonics, photonic integration, sensing, laser physics, nonlinear dynamics or signal processing is a plus.
• Good programming skills are a strong plus. Experience with Matlab, Python or a similar language and environment is a plus. Depending on the skills of the candidate, training can be arranged in the first year of the PhD.
• The candidate is expected to be able to carry out the research activities independently and in a critical manner, whilst having excellent communication skills and a positive attitude towards collaboration.
• Good time management skills are a must, along with the ability to meet tight deadlines and work efficiently under pressure.
• Proficiency in both spoken and written English (typically CEFR level C1 or equivalent) is required. The candidate will have the opportunity to take evening English classes to improve his/her language skills if needed.
• The candidates should be prepared to travel in Europe and potentially worldwide e.g. for participation in conferences or research stays at partner institutions.

Candidates that have not yet acquired their master’s degree can apply and participate in the selection procedure, but need to offer proof of registration in their Masters programme and need to have complied with all diploma requirements before starting their position at VUB.

The available PhD position has a normal duration of 4 years in Belgium.

The candidate is expected to endorse the educational vision of the university (full text available on the university website).

Female candidates are particularly encouraged to apply.

Required languages: Proficiency in both spoken and written English (typically CEFR level C1 or equivalent) is required.

Starting date: September - December 2024.

• A very competitive salary and benefits (holiday allowance, end-year bonus, commuting expense coverage, possibilities to work from home, eco-vouchers, attractive discounts via Benefits@Work, etc.) ;
• Being part of an international, multicultural team in Brussels, a city known for its international character and central location in Europe;
• Opportunities for learning new technical and transferable skills;
• Participation in national and international workshops and conferences;
• Fully funded research stays abroad (optional);Last but not least, a fantastic topic that is attractive to sci-fiction & pop science!

The main work location will be the VUB Photonics Campus at Vollezelestraat 46, 1755 Gooik, Belgium, as well as the VUB Humanities, Science and Engineering campus, Pleinlaan 2, 1050 Brussels, Belgium.

To apply, please send your detailed CV (including a copy of the Master's diploma and a Transcript of records), letters of recommendation, any supporting documents demonstrating technical skills (theses or scientific papers), and an application letter to Prof. Tigran Baghdasaryan. If no suitable candidate has been found after the deadline, the position will remain open until it is filled.

The selection process will take place in two steps: First, the file of each applicant will be carefully screened and reviewed. Well-suited candidates will be selected on this basis. Second, selected candidates will be invited to a teleconference interview during which they will be asked a broad set of technical and non-technical questions. Finally, all retained candidates will be ranked based on their academic records and their interview, and the candidate ranked 1^st will be offered the position.

The position will remain open until it is filled.

For more information, please contact Prof. Tigran Baghdasharyan or Prof. Martin Virte.

For 50 years, the Vrije Universiteit Brussel has stood for freedom, equality and connectedness. These values are strongly present on our campuses, in our students as well as our staff. At the VUB, you’ll find a diverse collection of personalities: pure innovators and especially people who are 100% their authentic selves. With about 3.500 employees, we are the largest Flemish-speaking employer in Brussels, an international city with which we are all too happy to be connected, and around which our four campuses are located.

At VUB, your days will be spent in a dynamic, diverse and multilingual environment. Our main campus is set within green oases on the outskirts of the centre of the capital of Flanders, Belgium and Europe. This centre, with all its opportunities, is within your reach by public transport in under half an hour. As an employee of the Vrije Universiteit Brussel, you will receive an attractive salary corresponding to one of the pay scales laid down by the government, depending on your experience and academic merits. Hospitalisation insurance and free use of public transport for travel to and from work are standard conditions of employment. If you would rather cycle to work, compensation is also available for that.

More information is available at www.vub.be.