The study of topological phases of light underpins a promising paradigm for resilient light manipulation by exploiting spatiotemporal symmetries of the system and dual symmetry of the electromagnetic field. Recent years witness increased interest and experimental progress in implementing topological states of light in a plethora of platforms, including metacrystals, arrays of microring resonators, polaritonic microcavities and optical waveguide lattices, that furthermore bridges to advances in quantum optics and nonlinear nanophotonics. Combining topological photonic structures with nonlinear effects is expected to unlock advanced functionalities such as magnet-free nonreciprocity and active tunability .
This project aims to explore how topological photonics can intertwine with nonlinear optics to enable robust signal processing, active control of topological properties and enhanced light–matter interactions. The topic involves research in theoretical and computational photonics and covers, in particular, self-localized nonlinear modes in topological photonic lattices , as well as light generation in topological cavities and nanophotonic metasurfaces . Harnessing topological designs will be examined as a means of improving the performance of nonlinear optical devices including light sources, lasers, frequency combs, and parametric amplifiers.
References  Applied Physics Reviews 7, 021306 (2020).  Laser & Photonics Reviews 13 (12), 1900223 (2019).  Physical Review Letters 123, 103901 (2019).