High peak power and gateable picosecond optical pulses from a diode array traveling-wave amplifier and a mode-locked diode laser

A traveling-wave amplifier made from an AlGaAs laser diode array has been used to selectively amplify individual pulses from a 250-MHz pulse train of a mode-locked laser diode. A coherent average output power of 35.3 mW was obtained for 14.2 mW incident on the final objective. Peak powers as high as 4.75 W have been obtained with application of both continuous and pulsed current to the amplifier. This represents a 5.7-fold enhancement of the peak power over the power of the incident signal. When the mode-locked laser source had a single spatial mode, the amplifier output was dominated by a single lobe, ∼0.82° wide.