Dramatic Reduction of the Amplitude Noise of Colliding-Pulse-Modelocking Dye Lasers

Abstract

The colliding pulse modelocking (CPM) dye laser has established itself as the work horse of femtosecond optics and spectroscopy owing to the ease of generating stable optical pulses of less than 100 fsec duration. The probably most important improvement of the CPM laser has been the addition of a four-prism sequence to adjust the intracavity group velocity dispersion [1]. Although the CPM laser has been object of extensive studies to understand the complex pulse forming mechanisms, the characterization of its amplitude noise has not received much attention. We show in this manuscript that the strong amplitude noise of the CPM laser at frequencies of several MHz can be significantly reduced by simply inserting a single frequency etalon in the cavity of the (argon-ion) pump laser.