Mode-volume and pump-power limitations in injection-locked TEM(00) Nd:YAG rod lasers

Stress-induced birefringence in cw-pumped Nd:YAG rods create stability limitations on the TEM(00) polarized mode of a resonant cavity. We present and verify experimentally a thermo-optical model describing a ring cavity containing a birefringent cw-pumped Nd:YAG rod. We use the model, along with experimental evidence, to show that a fundamental TEM(00) mode size and pump-power limitation exists for any cw-pumped Nd:YAG laser, implying a maximum allowable TEM(00) output. We show that the largest TEM(00) mode radius that can be supported in the rod is approximately 1.1 mm and is independent of the physical size of the rod.