Laser Levitation of Superfluid Helium
laser levitation, helium, evaporation, piezoelectric transducer
We describe experiments on the laser levitation of superfluid helium. Liquid drops of 10–20 m diameter are produced by a submerged piezoelectric transducer and suspended in vapor at 2K for up to 3 minutes. The optical trap is formed by two counter-propagating, horizontal, focused laser beams. Calculations show that Brillouin and Raman scattering of the laser light in the liquid helium produces a negligible rate of evaporation of the drop. Evaporation caused by the enhanced vapor pressure of the curved drop surfaces appears to be a significant effect limiting the drop lifetimes. We calculate the characteristics of the optical trap and the deformation of the liquid drops by the light forces. The observed simultaneous trapping of multiple drops is also discussed.
© 1995 Plenum Publishing Corporation; © Springer, Part of Springer Science+Business Media
Weilert, M.A., et al. "Laser Levitation of Superfluid Helium," in the Journal of Low Temperature Physics, Vol. 98, Nos. 1-2 (1995), 17-35. DOI: 10.1007/BF00754065