Solid-state lasers directly pumped by InGaN-based green and blue laser diodes

Development of solid-state lasers, titanium-doped sapphire and praseodymium doped LİYF4 lasers, directly pumped by indium gallium nitride-based green or blue semiconductor lasers is presented. We experimentally revealed the existence of an additional absorption induced at 450-nm pumping, and compared the laser performance with respect to the pump wavelength (450, 478 and 520 nm). A mode-locking operation is demonstrated with a pulse width of 126 fs and an average power of 315 mW. For Pr:LiYF4 lasers, power scaling up to 4.8 W is achieved utilizing four 3.5-W 445-nm diodes at 640 nm with a slope efficiency of 50%. Intracavity second harmonic generation of passively Q-switched laser at 320 nm and a SESAM mode-locking at 640 nm are also obtained.