Radiometric levitation of a 20-μ-diam dye-impregnated glycerol sphere has been observed at intensities as low as ∼1 W/cm2 in air at 30 Torr. The levitation has been effected on both strongly absorbing spheres in the direction of the light and weakly absorbing spheres in the opposite sense. Both strongly and weakly absorbing spheres are found to laterally seek an intensity minimum. Consequently particles were stably held in the focused beam of an Ar+ laser (4880 Å) operating in the TEM* 01 (doughnut) mode.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)