A 46-W Laser Diode Stack End-Pumped Slab Amplifier with a Pulse Duration of Picoseconds

A 46-W laser diode end-pumped amplifier is demonstrated by using a SESAM passively mode-locked oscillator and a compact LD stack end-pumped slab amplifier. For the oscillator, a 5-W picosecond mode-locked laser with a repetition frequency of 79 MHz is obtained with beam quality factors of M²<1.3. A beam shaping system made up of cylindrical lens is designed according to different sizes of the active medium in both directions, and a plane−plane cavity is used in the amplifier for high efficiency. At the absorbed pumping power of 174 W, the highest output power of 46 W is obtained with the slope efficiency of 29.5%. The beam quality factors M² in both directions are measured to be 1.43 and 1.76, respectively.