Multi-watt, high efficiency, diffraction-limited Nd:YAG planar waveguide laser

An efficient, longitudinally diode-pumped, diffraction-limited, Nd:YAG double-clad planar waveguide laser was operated on four transitions of the Nd3+ ion. Optimized output powers of 4.3, 3.5, and 2.7 W were obtained for absorbed pump powers of similar to 7 W, for the transitions at the lasing wavelengths of 1.064 mum, 946 nm, and 1.3 mum, respectively. Operation of the weak F-4(3/2) -->(4) I-5/2 transition, lasing at 1.833 mum, was demonstrated at an absorbed pump power threshold of 300 mW and an output power of 400 mW, with a nonoptimized output coupling. Diffraction-limited performance was obtained in both the guided and nonguided axes.