Actively Q-switched all-fiber laser with an electrically controlled microstructured fiber

Actively Q-switching of an all-fiber laser system is demonstrated. The active element is a polarization switch with nanosecond risetime based on a microstructured fiber with electrically driven internal electrodes. Optical feedback between two 100% reflectors is inhibited until a nanosecond current pulse Q-switches the laser. After a short optical pulse develops several roundtrips later, the fiber switch is turned off, removing the short optical pulse from the cavity through a polarization splitter. Pulses of 50 W peak power and approximately 12 ns duration are obtained with 400 mW pump power at 100 Hz.