“…Although they are very small when one uses ordinary light sources, these forces were also investigated experimentally in the beginning of this century by P. Lebedev, E. F. Nichols and G. F. Hull, R. Frisch. For a historical survey of this research field, we refer the reader to review papers (Ashkin, 1980;Letokhov and Minogin, 1981;Stenholm, 1986;Adams and Riis, 1997) which also include a discussion of early theoretical work dealing with these problems by the groups of A. P. Kazantsev, V. S. Letokhov, in Russia, A. Ashkin at Bell Labs, and S. Stenholm in Helsinki.…”