Tm^3+/Ho^3+ codoped tellurite fiber laser

Abstract

Continuous-wave and Q-switched lasing from a Tm 3+ /Ho 3+ codoped tellurite fiber is reported. An Yb 3+ /Er 3+ -doped silica fiber laser operating at 1.6 μm was used as an in-band pump source, exciting the Tm 3+ ions into the 3 F 4 level. Energy is then nonradiatively transferred to the upper laser level, the 5 I 7 state of Ho 3+ . The laser transition is from the 5 I 7 level to the 5 I 8 level, and the resulting emission is at 2.1 μm. For continuous wave operation, the slope efficiency was 62% and the threshold 0.1 W; the maximum output demonstrated was 0.16 W. Mechanical Q switching resulted in a pulse of 0.65 μJ energy and 160 ns duration at a repetition rate of 19.4 kHz. © 2008 Optical Society of America.