From rainbows to fibre optic magnetic sensors

3 Jun, 2020

As a child growing up in China, Fangfang Wei, a PhD student at TU Dublin, was always fascinated with optical properties such as the colours of a rainbow, the polarisation of a pair of sunglasses or the beam of a light pen.

When she discovered in Science class that a simple triple prism would produce a rainbow, Fangfang was inspired to learn more about what appeared to be the almost magical properties of light.

Her interest piqued, Fangfang received her Undergraduate degree in Communication Engineering from Inner Mongolia Normal University in 2009 followed by a Master’s Degree in Optical Communication Systems & Devices from Tianjin University of Technology. She worked as an Optical Research and Development Engineer in Beijing before joining TU Dublin in 2015 where her PhD research is about designing optical micro-fibre sensors and lasers in magnetic field inspection, a topic on which she has published over 15 journal and conference papers.

On why she chose TU Dublin to complete her PhD, Fangfang, said, “The field of Fibre Optics is new with most development taking place over the last 60 years or so. The experiment environments are expensive, and the work demands expertise of a very high standard. TU Dublin has an excellent reputation for quality research in my area as well an openness to collaborating with other Universities or Institutes across the globe. TU Dublin also provides support for postgraduate students in the form of a Scholarship which covers research and living expenses.”

Speaking about the real-world applications of her research, Fangfang says the invisible magnetic fields around us can affect our lives in many ways and are essential to many modern technologies in the electro-mechanics, navigation, aviation and space industries. “Magnetic field sensors made from optical fibres provide an excellent alternative to the traditional electronic sensing due to their outstanding advantages of immunity to electromagnetic interference, compact size, and ability to operate in hazardous environments. They could be used, for example, to detect changes in the magnetic fields on Earth that deflect most of the harmful radiation and hot plasma from the Sun into space. A fibre optic magnetic sensor could detect even the smallest of changes in this magnetic field to predict extreme weather events more accurately.”

At TU Dublin, Fangfang works with optical fibres, used to transmit light, to develop magnetic field sensors that are highly sensitive to changes in any given environment. Using a fusing technique, she fabricates microfibers and couplers with a radius of just 1~3 micrometres using a standard single-mode-fibre. She uses various magnetic material coatings to assess the strength and direction of the magnetic field. In addition to magnetic sensing, Fangfang is also interested in using optical fibre sensing structures to detect the refractive index of liquid, environmental temperatures and biomolecules.

Fangfang says life as a researcher can be tough, with long days in the labs, delays and even failure all normal. However, her supervisors, especially Prof. Yuliya Semenova, offer her lots of support and help her to solve any problems quickly. “Besides study, TU Dublin has provided me with many other opportunities to excel in my career; I have worked as an Assistant Lecturer for a year, and I was President of the TU Dublin student chapter of the SPIE (International Society for Optics and Photonics). I often meet with other students in the same field to discuss our research problems and help each other by sharing resources and knowledge. Life at TU Dublin is colourful, fun and exciting in so many ways.”

Read more about Fangfang Wei’s research here.

Read more about our PhD & Research Programmes Opportunities here.