Resonant spin Hall effect of light in random photonic arrays

It has been recently shown that the coherent component of light propagating in transver-sally disordered media, the so-called coherent mode, exhibits an optical spin Hall effect (SHE). In non-resonant materials, however, this phenomenon shows up at a spatial scale much larger than the mean free path, making its observation challenging due to the ex-ponential attenuation of the coherent mode. Here, we show that in disordered photonic arrays exhibiting Mie resonances, the SHE on the contrary appears at a scale smaller than the mean free path if one operates in the close vicinity of the lowest transverse-magnetic resonance of the array. In combination with a weak measurement, this gives rise to a giant SHE that should be observable in optically-thin media. Furthermore, we show that by additionally exploiting the cooperative emission of a flash of light follow-ing the abrupt extinction of the incoming beam, one can achieve a time-dependent SHE, observable at large optical thickness as well.

Automated summary

It has been discovered that the coherent mode of light propagating in transversely disordered media, known as coherent mode, exhibits an optical spin Hall effect (SHE). However, in non-resonant materials, this phenomenon appears at a larger spatial scale than the mean free path, making it challenging to observe due to the exponential attenuation of the coherent mode. In this study, we demonstrate that in disordered photonic arrays with Mie resonances, the SHE appears at a smaller scale than the mean free path if operated near the lowest transverse-magnetic resonance of the array. With weak measurement and cooperative emission, a giant SHE that can be observed in optically-thin media is achieved. Additionally, a time-dependent SHE observable at large optical thicknesses can be achieved by exploiting the cooperative emission of a flash of light following the abrupt extinction of the incoming beam.