Abstract

Light-induced drift (LID) of atoms and molecules arises from a combination of two effects. One of them is velocity-selective electronic- or vibrational-state excitation of species because of the Doppler effect. Another one is the difference in friction of the flows (difference in velocity-changing collision cross-sections) of excited- and ground- state particles with a buffer gas. Unlike light pressure, LID does not require momentum transfer from photons to particles, since two counterpropagating flows of absorbing and buffer gas, one through another, compensate each other. LID was originally proposed for excitation with monochromatic laser radiation.¹

© 1992 Optical Society of America