Аннотация:Spin–orbit interaction (SOI) is a striking physical phenomenon in which spin and orbital features of a particle or a wave
field affect each other. Recently, there has been significant
interest in the SOI of light as it accompanies a number of
fundamental light–matter interaction processes, enabling
intriguing applications. We demonstrate the spin-orbit coupling between photons and phonons, in contrast to recently
reported studies dealing with a “single-field” SOI. We show
that the spin angular momentum of phonons can be transformed into the orbital angular momentum of photons, and
vice versa, during the fiber acousto-optic interaction. This
results in the acoustic-spin-dependent, dynamically tunable
generation of topologically charged optical vortex beams
directly from a Gauss-like mode. This type of optical mode
conversion can be useful in such vortex-based photonics applications as micromechanics, classical and quantum information
technologies, and simulation of quantum computing. This
particular example of a “two-field SOI” shows that the concept of spin-orbit coupling can be generalized to describe
the interaction between elementary excitations of different
physical nature. Our findings indicate that SOI-assisted effects
might be found in physical systems with photon–phonon,
magnon–phonon, electron–phonon, and other interactions,
enabling tailored topologically charged multiparticle states
in photonics, spintronics, plasmonics, etc