Efficiency of an Li–Nd–La phosphate glass laser at low pump energies. Free lasing

An investigation was made of the free-lasing regime in a high-concentration Li–Nd–La phosphate glass pumped in the energy range 1–15 J. A laser efficiency of 2.9% was obtained for a pump energy of 14.5 J. Estimates were made of the intracavity losses and the maximum attainable efficiency was determined. An investigation was made of the laser performance in the giant pulse regime and at pulse repetition frequencies of up to 25 Hz.