Abstract

The radiative quantum efficiency of a laser transition is a key parameter for characterizing the performance of a solid-state laser or amplifier. Direct measurements of quantum efficiency with an integrating sphere can be difficult, however, requiring a careful calibration of the absolute response of the detector system.¹ In the case of rare-earth ions doped in a solid, there is an alternative approach, based on the Judd-Ofelt analysis of radiative transitions.² In this approach one obtains the quantum efficiency by comparing the measured fluorescence lifetime of the upper laser level to the radiative lifetime calculated by using the Judd-Ofelt theory. This is not truly a measured value of the quantum efficiency, however, since it is obtained by using a calculation (Judd-Ofelt analysis) that is subject to inherent uncertainties.

© 1995 Optical Society of America