A diode-pumped, high gain, planar waveguide, Nd:Y3Al5O12 amplifier

We report the use of a 5 mm long planar Nd:YAG waveguide grown by liquid-phase epitaxy as an amplifier at 1.064 µm. In a double-pass configuration pumped by a 1.2 W diode-laser, small signal gains of 686 (28 dB) have been observed and efficient power extraction demonstrated with output powers of up to 290 mW being obtained