Colloquium: Nonlinear topological photonics

Bo Zhen (University of Pennsylvania)
- | David Rittenhouse Laboratory, A4
Bo Zhen

Topological photonics is a rapidly developing field, often drawing inspirations from the recent successes in electronic systems. Yet there are a few major differences between photons and electrons, leading to different topological consequences. For example, photons obey Maxwell’s equations, which naturally permit classical nonlinearities; whereas electrons obey Schrodinger equation that is linear. Based on this difference, I will present our recent theoretical and experimental results in exploring the role of classical optical nonlinearity in topological physics. On the theory side, these include defining topological invariants in driven nonlinear photonic crystals [1], Floquet dipole phases [2], quadrupole phases [3,4], and polaritonic Chern insulators [5]. On the experimental side, I will present our recent experimental demonstration of Floquet Chern insulators [6]. Finally, I will conclude with an outlook for future research and potential applications, such as night-vision goggles and room-temperature far-infrared light detectors. 



[1] Nature Communications 10. 4194 (2019) 

[2] Physical Review Letters 126, 113901 (2021) 

[3] Nature Communications 11, 3119 (2020) 

[4] Physical Review Letters 129, 063902 (2022) 

[5] Physical Review Letters 130,  043801 (2023) 

[6] arXiv:2304.09385