Spin of random stationary light

Abstract

We develop a theoretical foundation for the spin angular momentum (SAM) of random, statistically stationary polychromatic light fields within the framework of classical optical coherence theory. The formulation is valid for fields of arbitrary frequency bandwidth and dimensionality. Both temporal and spectral representations are given, and we further elucidate the relationship between the SAM and the polarization characteristics of such fields as compared to monochromatic light. The special cases of quasimonochromatic light and planar fields are analyzed separately. Generally, our paper offers deeper insights into the SAM and polarization structures as well as their interlinked connections in random stationary light, which could be beneficial in exploiting SAM in stochastic optical near fields and tightly focused beams exhibiting complex polarization character.

Spinning a levitated mechanical oscillator far into the deep-strong coupling regime

“…In contrast, the circularly polarized beam generates a non-conservative torque, which drives the dumbbell into a spinning motion around its long axis. This torque arises from the optical spin [29,30] carried by the beam together with absorption or imperfect cylindrical symmetry of the dumbbell [31Ű33].…”