Two-Photon Absorption from a Phase-Diffusing Laser Field

Abstract

We report the first quantitative measurements of the effect of a phase-diffusing laser field on a nonlinear optical interaction. Using a nearly Lorentzian laser power spectrum, we have measured the spectral linewidth of an unsaturated two-photon absorption process. We find that the measured width scales as four times the laser width, in agreement with the theoretical predictions of Mollow.