Abstract

According to a postulate of quantum mechanics, the probability of a transition from state |n′J′M′〉 to state |n″J″M″〉 is controlled by the absolute square of the matrix element 〈n′J′M′|O|n″J″M″〉 in which O is the operator responsible for the transition, J is the total angular momentum quantum number, M is the quantum number for the z-component of the total angular momentum, and n denotes all other required quantum numbers. By definition, the sum of all such squared matrix elements which contribute to the same observation is called the line strength.1-4 Thorne’s table 9.1³ gives the for the Einstein coefficients and the oscillator strength in terms of the electric dipole line strength.

© 1996 Optical Society of America