Towards a space-qualified Kerr-lens mode-locked laser

We report a 1.5-GHz Kerr-lens mode-locked (KLM) Yb: Y 2 O 3 ring laser constructed by directly bonding the cavity components onto an aluminum baseplate. Stable unidirectional operation with an output power ≥ 10 m W was obtained for pump-diode currents of 300–500 mA, corresponding to a total electrical power consumption of 1.5 W. After repetition rate stabilization, a comparison with a conventionally constructed identical laser showed a 50% reduction in phase noise. In free-running operation the bonded laser showed superior passive repetition rate stability. The bonding process follows an already proven integration approach in space-borne instrumentation, mapping a development pathway for KLM lasers in aerospace applications.