Optimization of Erbium-Doped Actively Q-Switched Fiber Laser Implemented in Symmetric Configuration

We report the results of an experimental study aimed at improving the performance of actively Q-switched fiber lasers. Unlike generic design schemes employing photonic crystal fibers, large modal diameter fibers or double-clad fibers, we demonstrate a high-power, actively Q-switched laser based on standard communication erbium doped fibers with peak irradiance beyond the state-of-the-art at 3.1 GW/cm
²
. The laser had 2.2 kW peak power, 15.5 ns pulse duration and 36.8 μJ pulse energy. We have also investigated the dynamics of pulse generation and have successfully suppressed pulse instabilities caused by backscattered laser emission reaching the pump laser diodes.