High power linearly polarized diode-side-pumped Nd:YAG laser based on an asymmetric flat–flat resonator with the variable working point

A high power linearly polarized diode-side-pumped Nd:YAG laser is demonstrated based on an asymmetric TEM00-mode flat–flat cavity with the birefringence compensation. Different from the traditional dynamically stable resonator, an asymmetric flat–flat resonator with the variable working point is designed theoretically and experimentally. Both of the Nd:YAG rods have a dimension of Φ5 mm × 130 mm and a doping concentration of 0.6 at.%. Under the pump power of 570 W, the maximum unpolarized output power of 111.7 W is achieved with an optical–optical efficiency of 19.6%. Using a Brewster plate, a linearly polarized output power of 80.1 W is obtained with the polarization extinction ratio of 18 dB, corresponding to the beam quality factors of ∼3.38 and ∼2.83 in the horizontal and vertical directions, respectively. To the best of our knowledge, this is the highest linearly polarized output power for a side-pumped two-rod Nd:YAG laser system with the asymmetric resonator. •An asymmetric flat–flat resonator with the variable working point is designed.•Both of the Nd:YAG rods have a dimension of Φ5 mm × 130 mm and a doping concentration of 0.6 at.%.•A linearly polarized output power of 80.1 W is obtained at 1064.1 nm based on side-pumped Nd:YAG modules.