3 J/1 Hz opposite diode-pumped Yb:YAG active mirror amplifier at room temperature

Experimental amplification of 10-ns pulses to an energy of 3 J at a repetition rate of 1 Hz is reported from an opposite diode-pumped Yb:YAG-based active mirror amplifier at room temperature.Meanwhile, we have conducted the crystal packaging, amplified spontaneous emission (ASE) suppression, coating design, and pump energy storage.The gain characteristics dependence on pump pulse duration, cooling-water temperature, and repetition rate are studied.The compact amplifier employs symmetrically placed active mirror amplifiers, with a 2-m optical length and a footprint of 60×80 cm 2 .Thanks to Gaussian spatial profile of the beam, no telescope was required in the entire amplifier chain.The validated concept of the compact active mirror amplifier shows potential for scaling energy up to 50 J or beyond by incorporating additional active mirrors into the chain, especially seeding with a pulse energy of ×100-mJ at repetition rate of 1-10 Hz.