207 / 2023-04-15 20:20:12

Photons and plasmons with orbital angular momentum in magnetized plasma

helical wavefront,eigenmode,orbital angular momentum,dispersion relation

辐射和流体力学 > 辐射和流体力学-海报

The dispersion relations of eigenmodes in plasmas were well-known in the form of plane wave approximations. Recently waves with helical wavefronts relating to the orbital angular momentum (OAM) were gaining increasing attention both in laser plasma physics and magnetized plasma physics, like the vortex beam plasma interaction for particle acceleration and the low-frequency helical whistler waves in magnetized plasma for plasma ionization. It was identified the exact eigenmodes with helical wavefronts in unmagnetized plasma were determined by two wavevectors. Here we derive the dispersion relations of eigenmodes with OAM in magnetized plasma. It is found that like those in unmagnetized plasma, the eigenmodes with OAM also have two wave numbers. When the transverse wave number is appreciable, the cutoff frequency of the electromagnetic waves can be significantly lower than the electron cyclotron frequency. The present properties may furnish potential applications in plasma physics and space physics.