Abstract

Nd³⁺-doped bismuth germanate crystal (Bi_4xNd_xGe₃O₁₂) is a cubic crystal with symmetry 43m structure, grown by the Bridgman technique. Nd:BGO is a promising laser medium as well as a useful magneto-optic material. Its stimulated cross section of 1.34 × 10^-19 cm^-2 and fluorescence lifetime of 320 μs were measured for a BGO crystal with Nd-doped 1 wt%. The product of σ and τ is four times that of Nd:glass. A diode laser-pumped Nd:BGO laser has succeeded, we believe for the first time. The Nd:BGO is 5 mm long and 5-mm diameter. Adopting a conjugate imaging technology, the diode laser radiation is focused to an end-pumped monolithic Nd:BGO laser. An output power of cw 40 mW with TEM₀₀ mode, 20% efficiency, and repetition rate of 1 kHz have been obtained. The pumping threshold is 15 mW.

© 1993 Optical Society of America