We report on the performance of highly efficient, high-power continuous-wave (CW) Nd:YAG lasers that are side pumped by <i>p</i>-polarized diode laser beams. In this configuration pump light is directly coupled into the Nd:YAG rod through a threefold symmetric gold-coated flow tube. The polarization direction of our pump diode bars is perpendicular to the rod’s axis (<i>p</i>-polarized). In a closed coupled resonator, a maximum output power of 195 W in multimode operation is obtained for a pump power of 423 W, which corresponds to an optical-to-optical efficiency of 46% and an electrical-to-optical efficiency of 23%. This is, to the best of our knowledge, the highest electrical-to-optical efficiency reported for a CW diode side-pumped Nd:YAG laser. By the pump-power leakage analysis method, we measured the pumping efficiency to be approximately 94%. The high efficiency of the system can be attributed to wing pumping, which results in uniform pump-light distribution and better pumping efficiency because of the use of <i>p</i>-polarized pump beams.
© 2004 Optical Society of America
Ranganathan Kandasamy, Sundar Raghavachari, Puskar Misra, and Sthanu Nathan. T. P, "Highly Efficient Continuous-Wave Operation of a Nd:YAG Rod Laser that is Side Pumped by p-Polarized Diode Laser Bars," Appl. Opt. 43, 5855-5859 (2004)