Abstract
Data are presented which show that it is possible to observe transitions for which ΔJ=0, ΔmJ=±2 or ±3 in a molecule characterized by a total angular J. It is also possible to observe transitions for which ΔF=0, ΔmF=±2 or ±3 in an atom characterized by a total angular momentum F. In each case the process occurs by the absorption or stimulated emission of two or three equienergetic quanta.