Effects of Transverse-mode Profile on Slope Efficiency and Relaxation Oscillations in a Longitudinally-pumped Laser

Abstract

Measurement of relaxation oscillation frequency can provide a convenient means for measurement of laser resonator losses. Expressions are derived which take account of the effect of non-uniform pump and laser beam profile on relaxation oscillation frequency and slope efficiency for a longitudinally-pumped four-level laser. Significant departures from plane-wave calculations are found. It is also shown that by combining a measurement of slope efficiency and relaxation oscillation frequency, the loss can be deduced without detailed knowledge of the pump beam profile. Experimental results supporting these calculations are described.