It is our pleasure to announce that Alba Paniagua has recently submitted her PhD thesis on “Light in scattering media: active control and the exploration of intensity correlations” (abstract below), supervised by Jacopo Bertolotti and Bill Barnes.
Alba is a driven researcher with strong leadership qualities. For example, she represented her peers as member of the CDT Student Advisory Group in discussions with the Management and Oversight Boards (2016/17), and became the first female president of the international society for optics and photonics (SPIE) student chapter at Exeter (2015/16). During that time she built bridges between SPIE and the College’s Early Career Researcher Network to co-host a workshop on Careers in Optics for the benefit of all interested postgraduate and postdoctoral researchers.
Alba has presented her research at several national and international conferences, such as Optics & Photonics in San Diego (CA) or CLEO Europe in Munich, and is currently writing 3 research papers to publish the results of her PhD project.
She is planning to continue her research for 3 more months as a postdoc at Exeter, and is looking forward to taking some time in summer 2018 to identify her next steps and careers options. Alba’s home country Spain is close to her heart, and will hopefully be able to offer her good job opportunities in the future, but in the meantime she has set her mind on exploring the wider world within and outside the research community, e.g. in Australia or in the US, to widen her expertise and network.
A highlight of Alba’s PhD studies was the extended research stay at the Fraunhofer Center of Applied Photonics in Glasgow in 2017, where she worked with Dr David Stothard, Deputy Head of Department, Lasers and Laser Systems and his research team on building a ring cavity laser – an experience she highly values and recommends to any postgraduate researcher.
The CDT’s “Beyond A PhD” speakers were of particular inspiration to Alba, as the visiting speakers (e.g. Helen Thomas, BBC executive producer) helped her to understand that there is a myriad of careers pathways open to a doctoral graduate in Physics. “It was eye opening to learn how many opportunities one can have – in academia, industry and beyond – and that it’s not just black and white but full of unexpected turning points.”
Alba used several opportunities to share her passion for research with the wider public, e.g. through experiments at the IOP Festival of Physics (2014), the Physics Open Days (2015 & 2016) and the Big Bang event (2016) at Exeter. She particularly enjoyed working with groups of school children and the watching the fascination in their eyes when the magic of Physics unfolds in front of them.
We are incredibly proud of Alba and have no doubt that she will successfully pass the viva as her final step towards the PhD degree. Looking a few years ahead it will be our pleasure to welcome her back at Exeter as a “Beyond a PhD” speaker to inspire future generations by sharing her experiences after graduating from the CDT in Metamaterials.
Abstract of Alba Paniagua’ s PhD thesis
Light in scattering media: active control and the exploration of intensity correlations
When light encounters scattering materials such as biological tissue, white paint or clouds, it gets randomly scattered in all directions, which traditionally has been seen as a barrier for imaging techniques (reducing their resolution) or sensing, due to the reduction of the penetration depth of light. However, in recent years it has been shown that scattering might not necessarily be an impediment, and that the knowledge of the properties of multiple scattering can be indeed useful for imaging, sensing and other applications.
In the first part of this thesis we study the implications of manipulating the light incident on a multiply scattering material. We experimentally show how by actively controlling the output light of a bad quality laser we manage to not only improve its beam quality, but also in an energy-efficient way, in comparison with traditional methods. In a different experiment presented in this thesis, we show how the active control of the light incident on a scattering material can be useful to improve sensing through scattering media, by means of increasing the transmission and energy deposited inside.
In the final part we present the first experimental observation of intensity correlations between transmitted and reflected patterns from a scattering material, exploring how it depends on the parameters of the scattering medium. In the last part of the thesis we present a new imaging technique based on the use of the intensity correlations described in the previous chapter, opening new possibilities to non-invasive imaging through highly scattering materials.
