Coherently combined fiber CPA system delivering 3-mJ femtosecond pulses

The coherent combining of ultrashort pulses is a concept for scaling the pulse energy and average power of laser systems emitting ultrashort pulses. In this contribution the experimental results of a coherently combined femtosecond fiber CPA laser system consisting of 2 amplifiers is presented. Combining efficiencies as high as 89% and compressed pulse energies of up to 3mJ were achieved. Additionally, the system showed excellent long-term stability.