Nonlinear Frequency-Dependent Diffraction Effect in Intracavity Resonance Asymmetries

Abstract

The asymmetry observed in intracavity resonances (especially of the Lamb-dip type) is attributed to a resonant nonlinear diffraction effect. Direct evidence of this effect is obtained by a new experiment and careful analysis of the diffracted light, in the geometrical shadow of the laser beam inside the cavity, which reveals a reversed asymmetry of the resonance. A modified Lamb-dip formula gives better agreement between experiment and theory. The effect occurs in many experiments with Gaussian beams, particularly in recent high-sensitivity intracavity laser spectroscopy.