Simple method for compensation of thermally-induced birefringence in high-power solid-state lasers

Progress in power-scaling diode-pumped lasers has been hindered by thermal effects; notably thermal lensing and stress-birefringence. For applications requiring a linearly polarised output (e.g. nonlinear frequency conversion and Q-switching), the most serious problem is the depolarisation loss resulting from stress-induced birefringence which dramatically reduces the efficiency of low gain lasers at high pump powers. Various techniques for compensating stress-induced birefringence have been described (e.g. [1],[2]), but which are not well-suited for low gain end-pumped lasers employing a single laser rod.