Beam-quality improvement of a passively Q-switched Nd:YAG laser with a core-doped rod

We present experimental results that demonstrate the great efficiency of a core-doped Nd:YAG rod (a hexagonal Nd:YAG core surrounded by undoped YAG) in producing high output power and excellent beam quality. An additional improvement in beam quality is clearly observed when the core-doped rod is used in combination with a LiF:F(2)(-) crystal, which acts as a passive Q-switching element. This improvement is quantified by beam-propagation factors as low as M(2) approximately = at a maximum average output power of 9 W. We show that transversally pumped core-doped rods with the addition of LiF:F(2)(-) crystals fulfill the requirements for high-beam-quality, scalable, compact all-solid-state lasers in passively Q-switched operation.