Low-noise passive harmonically mode-locked Yb:CALCO laser oscillator

Harmonic mode-locking of a solid-state bulk laser combines the benefits of long resonators with large pulse energy and high repetition rates. With this technique it is possible to operate a system at different repetition rates without changing the optical setup. The signal to noise ratio of a fundamentally mode-locked oscillator is typically much better than in harmonic operation [1]. In this contribution we present a SESAM based solitary mode-locked diode pumped Yb:CALGO bulk oscillator. This system provides femtosecond pulses at a fundamental repetition rate of 94 MHz. For the second order harmonic mode-locking operation at the repetition rate of 188 MHz and the third harmonic at 282 MHz we have only to increase the pump power. At both operation points we need no active stabilization for a long term low signal to noise operation.