Abstract

The laser is responsible for the discovery and investigation of many nonlinear spectroscopic processes. Of increasing interest among these is two-photon resonant absorption.^1,2 Two-photon absorption allows the examination of atomic and molecular states that lie in a higher-energy region than is normally accessible by a one-photon process. This is due to parity considerations. Two-photon resonant spectroscopy tends to be less sensitive to fluctuations in the laser light source and, therefore, yields more easily reproduced data than nonresonant multiphoton spectroscopy.

© 1987 Optical Society of America