70W, 1MHz, sub-50fs Yb-Doped Fiber Laser System for High Harmonic Generation

We report the development of an ultra-fast, high repetition rate, high-power fiber laser system at 1 μm for high harmonic generation (HHG) to be deployed in a Tr-ARPES setup [1], that is currently served by a lower repetition rate Ti:Sapphire system. HHG is based on a non-linear interaction between intense laser pulses and a gaseous medium leading to the generation of short, coherent extreme UV (XUV) pulses [1]. The laser system required for efficient HHG should provide high-energy ultrashort pulses. Moreover, Tr-ARPES based on the detection of weak photo electron pulses requires a high repetition rate source [2] to maximize signal while minimizing acquisition times. Therefore, the HHG laser system with a high pulse repetition rate and peak power is necessary.