Pulse compression of a high-power thin disk laser using rod-type fiber amplifiers

We report on two pulse compressors for a high-power thin disk laser oscillator using rod-type fiber amplifiers. Both systems are seeded by a standard SESAM modelocked thin disk laser that delivers 16 W of average power at a repetition rate of 10.6 MHz with a pulse energy of 1.5 mu J and a pulse duration of 1 ps. We discuss two results with different fiber parameters and different trade-offs in pulse duration, average power, damage and complexity. The first amplifier setup consists of a Yb-doped fiber amplifier with a 2200 mu m(2) core area and a length of 55 cm, resulting in a compressed average power of 55 W with 98-fs pulses at a repetition rate of 10.6 MHz. In the second system, a shorter 36-cm fiber with a larger core area of 4500 mu m(2) is used. In a stretcher-free configuration we obtained 34 W of compressed average power and 65-fs pulses. In both cases peak powers of > 30 MW were demonstrated at several mu J pulse energies. The power scaling limitations due to damage and self-focusing are discussed. (c) 2011 Optical Society of America