PhD in Optical fibre sensing for ultra-high-pressure rheometry Vrije Universiteit Brussel (VUB) in Belgium

Vrije Universiteit Brussel (VUB) is offering a PhD position within the Faculty of Engineering, Department of Applied Physics and Photonics, in the Brussels Photonics research group (B-PHOT). The project is part of RheoLub, a Research Foundation - Flanders (FWO)-funded collaboration aimed at developing advanced experimental and modelling methods to understand industrial lubricants under extreme operating conditions.

The PhD research focuses on optical fibre sensing for ultra-high-pressure rheometry. The central goal is to design, develop, calibrate, and validate miniature fibre-optic sensors capable of measuring pressure and temperature inside a new generation of ultra-high-pressure rheometers. The work targets a slit-die rheometer cartridge in which optical fibres are integrated close to the lubricant flow channel to enable spatially resolved pressure and temperature profiling under very high pressures, high temperatures, and high shear rates.

The research program includes numerical design of sensor integration strategies, development of arrays of Fiber Bragg Grating (FBG) sensors in standard single-mode and/or microstructured fibres, investigation of pressure-sensitive fibre concepts such as the Butterfly microstructured optical fibre developed at VUB, and sensing approaches based on birefringence. The project also involves high-pressure calibration experiments, analysis of pressure-temperature cross-sensitivity, spectral data processing, temperature compensation, and conversion of measured strain into pressure. Sensor integration and validation will be done in close collaboration with Ghent University, which is developing the rheometer cartridge, thin-film reference sensors, and digital-twin-based methods for extracting material properties.

The successful candidate will join an internationally oriented photonics group and will be supervised by Prof. Francis Berghmans and Dr Sidney Goossens. The position may include limited teaching-related duties such as supervising practical sessions or master’s thesis students, but these tasks will remain minor and aligned with the research schedule.

Applicants should hold a Master’s degree in engineering, physics, photonics, applied physics, electrical engineering, mechanical engineering, materials science, or a related field. Candidates who have not yet completed the degree may still apply if they can provide proof of enrolment and satisfy all degree requirements before starting. Required skills include a strong interest in photonic sensing, optical fibre technology, and experimental research; knowledge of photonics, fibre optics, FBGs, optical sensing, signal processing, and/or experimental optics; and good English communication skills. Experience with MATLAB, Python, LabVIEW, COMSOL Multiphysics, finite-element modelling, optomechanical simulations, sensor integration, bonding, coatings, high-pressure testing, and instrumentation is considered beneficial.

The appointment is offered as a full-time PhD scholarship for 12 months, extendable up to 48 months based on positive evaluation, with a planned start date of 01/01/2027. The scholarship includes a grant linked to government scales. The main workplace is the Brussels Humanities, Sciences & Engineering Campus in Etterbeek, with regular activity also possible at the Photonics Innovation Center in Pajottegem.

Applications must be submitted through jobs.vub.be by 30 September 2026. Candidates should upload a CV, motivation letter, and diploma if applicable. Questions about the job content can be directed to Sidney Goossens at [email protected].