OSCILLATION CHARACTERISTICS OF DIODE-PUMPED TM-YAG AND TM,HO-YAG MICROCHIP LASERS

We have studied the output power, slope efficiency and oscillation threshold of a diode-pumped Tm:YAG microchip laser by using two different resonator configurations (half-symmetric and near-planar) for the development of an eye-safe remote sensing laser system. The half-symmetric resonator was superior in output power, slope efficiency and threshold, their values for a crystal temperature of 20 degrees C being 29 mW, 37%, and 28 mW, respectively. But the near-planar resonator was superior in producing single mode oscillation, giving an output power of 2 mW at a crystal temperature of -10 degrees C. Between Tm:YAG and Tm,Ho:YAG microchip lasers, moreover, the latter was found to fall short in slope efficiency and threshold, indicating that the effects of Ho as a dopant on the output power is negative. Possible explanations for the difference are given. (C) 1995 American Institute of Physics.