Abstract

Under the electric-dipole approximation, the signal of n-photon parametric processes in any molecular medium depends on the appropriate optical susceptibilities, χ⁽ⁿ⁻¹⁾, while these in turn depend on the molecular transition dipole moments The product of these transition moments connects the initial and final state, which in a parametric process are identical (usually the ground state 0). The route between the initial and the final state accommodates a complete sum over sets of intermediate states.

© 1998 IEEE