The University of Bath is inviting applications for the following PhD project supervised by Dr Peter Mosley (https://people.bath.ac.uk/pjm36/
), Dr Anton Souslov (https://researchportal.bath.ac.uk/en/persons/anton-souslov
) and Dr Josh Nunn (https://researchportal.bath.ac.uk/en/persons/josh-nunn
) in the Department of Physics.
This project will develop photonic crystal fibres that allow for robust light propagation due to topological protection using the fibre’s structure. Recently, the paradigm of topologically protected waves has found great experimental success across a wide range of physical phenomena, underpinned by advanced theoretical tools in topology. For example, the early theoretical work in topological electronics recognised by the 2016 Nobel Prize in Physics has led directly to the ongoing development of topological quantum computing. A challenge in photonics has been to realise topological protection within a scalable and practically exploitable platform. Optical fibres and fibre-optic cables underpin much of the current photonics technology, from the transmission of information in which topological robustness could offer greater transmission fidelity to imaging applications where topological scatter-free waves have the potential to enhance resolution.
Micro-structured optical fibre presents a sufficiently broad design space to realise topological states. Light waves are protected when they occur at interfaces of topological materials. The project will consist of two parts: (1) using an optical fibre to replicate the phase-engineered design of crystalline structures that have led to topological photonic states in other platforms (for example, laser-etching in silica, Ref.) and (2) designing defects, such as dislocations and vacancies, into the structure of the fibre cross-section, which will then act as waveguides to topologically protected modes. The student will explore these design ideas, modelling the fibre numerically in order to optimise the final design, along with fabrication of bespoke microstructured fibre and experimental characterisation of topologically protected modes.
A particularly appealing feature of a fibre implementation is the capability to tightly confine intense fields within long segments of material. This opens the possibility to engineer lattice couplings that are mediated by non-linear scattering, for example forward Brillouin scattering, in which cores are acoustically coupled, or four-wave mixing, in which cores are coupled via an optical idler field. Couplings of this kind are inherently non-reciprocal and can be configured to simulate gauge fields.
The project will provide the opportunity to undertake both modelling and experimental work, requiring the development and design of micro-structured fibres based on advanced theoretical concepts in topological photonics. The project is closely aligned with existing well-funded research into photonic quantum networks, nonlinear frequency conversion, Brillouin quantum memories, and with the research of Dmitry Skryabin in the area of topological photonics. The research will also involve theoretical and modelling contributions from Anton Souslov, Dmitry Skryabin, and Marcin Mucha-Kruczynski. The project will bring together members of three research groups within the department of physics: Photonics (and CPPM), Nanoscience, and Theory. It will allow for cross-disciplinary collaboration that involves translating well established theoretical tools into exciting technological innovations.
Applicants should hold, or expect to receive, a First Class or good Upper Second Class Honours degree (or the equivalent). A master’s level qualification would also be advantageous. It is essential that applicants have enthusiasm for modelling and experimental work for the development and design of micro-structured fibres and a theoretical background sufficiently strong to learn the core concepts underlying topological photonics.
Enquiries and applications:
Informal enquiries are welcomed and should be directed to Dr Peter Mosley on email address [email protected]
Formal applications should be made via the University of Bath’s online application form for a PhD in Physics: https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUPH-FP01&code2=0014
More information about applying for a PhD at Bath may be found here: http://www.bath.ac.uk/guides/how-to-apply-for-doctoral-study/
Anticipated start date: 28 September 2020.
Research Council funding is available for an excellent UK or EU student who has been ordinarily resident in the UK since September 2017. For more information on eligibility: View Website.
Funding will cover UK/EU tuition fees, maintenance at the UKRI doctoral stipend rate (£15,009 per annum tax-free in 2019/20, increasing annually in line with the GDP inflator) and a training support grant (£1,000 per annum) for a period of up to 3.5 years.
We also welcome all-year-round applications from self-funded candidates and candidates who can source their own funding.
1. A. Souslov et al. Topological sound in active-liquid metamaterials. Nature Physics 13, 1091 (2017);
H. Abbaszadeh*, A. Souslov* et al, Sonic Landau Levels and Synthetic Gauge Fields in Mechanical Metamaterials. Physical Review Letters (2017).
2. P.J. Mosley et al. Characterizing the variation of propagation constants in multicore fiber. Optics Express 22, 25689 (2014); R.J.A. Francis-Jones, R.A. Hoggarth, P.J. Mosley. All-fiber multiplexed source of high-purity single photons. Optica 3, 1270 (2016)
3. M.C. Rechtsman et al. Photonic Floquet topological insulators. Nature 496, 196 (2017).