Diode-laser edge-pumped Nd:YAG/YAG lens-shaped composite laser

Abstract A laser configuration made of a thin-disk Nd:YAG/YAG composite medium that consists of a circular Nd:YAG core bonded by diffusion to a circular undoped YAG and that has the shape of a plane-concave lens is presented. The pump is done through the undoped YAG edge, in a three-fold scheme, directly from the diode-laser optical fibers. Such a laser was built employing a Nd:YAG/YAG ceramics made of a 1.0-at.% Nd:YAG core of 2.0-mm diameter surrounded by a 10 mm in diameter YAG. The thickness was 180 μm at the center of Nd:YAG and 500 μm at the YAG edge. The Nd:YAG/YAG medium was attached to a water-cooled copper finger. At 2 Hz repetition rate the laser yielded pulses at 1.06 μm with energy E p  = 31.8 mJ under the pump at 807 nm with total energy E pump  = 114.6 mJ; the slope efficiency was 0.31. A decrease of laser pulse energy with the repetition rate was observed. This indicates that a better thermal management, which could be made through metallic bonding of Nd:YAG/YAG to the cooling system, is necessary.