Frequency stabilization and actuator characterization of an ytterbium-doped distributed-feedback fiber laser for LISA

We have investigated an ytterbium-doped distributed-feedback fiber master oscillator power amplifier system emitting 1 W and its suitability for the space-borne interferometric gravitational-wave detector Laser Interferometer Space Antenna (LISA). For this purpose we measured the laser system's free-running frequency noise, characterized its frequency actuator, and implemented a robust frequency stabilization. Up to 100 Hz Fourier frequency the free-running frequency, noise was comparable to that of a nonplanar ring oscillator. The first resonance of the actuator was at 32 kHz with a quality factor of 26 and a delay of 20 mu s. The frequency lock to a thermally shielded Fabry-Perot cavity was stable over many hours and fulfilled the LISA requirements. (C) 2009 Optical Society of Americ