Abstract

The problem of cw lasing of the Er^{3+ 4}I_11/2 ⁴I_13/2 transition in fluoride fibers has often been discussed. Lifetime measurements in Er³⁺-doped fibers revealed that the 2.7 μm transition is self-terminating. Pumping at 650 nm, the measured lifetimes are 9 ms for ⁴/_13/2 and 7 ms for ⁴I_11/2.¹ Laser performance and lifetime measurements in Er:Pr oo-doped ZULAN fibers with low Er³⁺ (1000 ppm) and high sensitizer concentration (1000-10000 ppm) have already been reported. Allain et al.² showed a reduction of lifetimes upon increasing Pr³⁺ concentration down to 4 ms (⁴I_11/2) and below 0.1 ms (⁴I_13/2). The best laser performance occurred at 1000 ppm sensitizer concentration.

© 1994 Optical Society of America