Abstract:
Stimulated emission due to the 4I11/2–4I13/2 transition (λ = 2.936 μ) in yttrium aluminum garnet (Y3Al5O12) doped with Er3+ ions (30 wt%) was observed for the first time at 300°K. The output energy from crystals of 50×3 mm dimensions was 0.3 J under free-oscillation conditions and 0.05 J in the case of Q switching. The lifetime of the 4I11/2 level was determined for crystals with 3–30 wt% Er3+. The energy from the higher Er3+ levels relaxed in a cascade manner through 4I11/2 to 4I13/2.