Measurements of cavity losses in diode-pumped lasers

Two methods of loss measurements: Findlay-Clay's method and relaxation frequency method were verified for two types of diode pumped lasers. In case of Nd:YAG laser with changeable output coupler the results obtained in both methods were in good agreement. However there was observed the contradictory between the relatively high losses (about 10% for transmission losses of 5%) and very high slope efficiency (approximately 50%) of this laser. The measurements of cavity losses via relaxation method were carried for several types of microlasers made of Nd:YAG, Nd:GGG, Nd:YAG crystals and Nd:phosphate glass. There were obtained total losses (including transmission ones) in the range from 7% to 30%.