Radiation pressure exerted on a spherical particle by one extremely fo
cused Gaussian beam is investigated by the use of generalized Lorenz-M
ie theory (GLMT). Particular attention is devoted to reverse radiation
pressure. GLMT predictions for different descriptions of the incident
beam are compared with electrostriction predictions when the particle
size is smaller than the wavelength and with geometric-optics predict
ions when the particle size is larger than the wavelength. (C) 1996 Op
tical Society of America