Gain-switched laser diode seeded Yb-doped fiber amplifier delivering 11-ps pulses at repetition rates up to 40-MHz

摘要

Here, we demonstrate all-fiber direct amplification of 11 picosecond pulsesfrom a gain-switched laser diode at 1063nm. The diode was driven at arepetition rate of 40MHz and delivered 13$\mu$W of fiber-coupled average outputpower. For the low output pulse energy of 0.33pJ we have designed a multi-stagecore pumped preamplifier based on single clad Yb-doped fibers in order to keepthe contribution of undesired amplified spontaneous emission as low as possibleand to minimize temporal and spectral broadening. After the preamplifier wereduced the 40MHz repetition rate to 1MHz using a fiber coupled pulse-picker.The final amplification was done with a cladding pumped Yb-doped large modearea fiber and a subsequent Yb-doped rod-type fiber. With our setup we achievedamplification of 72dBs to an output pulse energy of 5.7$\mu$J, pulse durationof 11ps and peak power of >0.6MW.