Effective cross section of the Nd:YAG 1.0641-μm laser transition

Abstract
The cross section of a laser transition is one of the most important parameters, because via the saturation intensity, Is=hν/(στ), the output power depends on it. For the Nd:YAG 1.0641‐μm laser transition, the published values vary between 4×1019 and 8.8×1019 cm2, as obtained by spectroscopic methods. This paper deals with a new method, which determines σ from the absolute value of the output power, the small‐signal gain, and the losses. Moreover, the extraction efficiency is evaluated, taking into account the mode structure.