Z-scan Measurement of the Upconversion Coefficient in Er:YAG
Final rept. Jun 2008-Aug 2009
ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
Pagination or Media Count:
Solid-state laser research at the U.S. Army Research Laboratory ARL is currently emphasizing techniques for power scaling and achieving wavelengths in the eye-safer spectral region. We are studying erbium-doped yttrium aluminum garnet ErYAG, because it can be operated with a low quantum defect and has transitions around 1.6 micrometers. However, it suffers from cooperative pair upconversion, which can raise the lasing threshold, and thus lower the output power. In this report, we demonstrate how to measure the upconversion coefficient Cup using the z-scan technique with a continuous wave source. We find Cup to be proportional to Er, for concentrations ranging from 0.5-5. The value we find at 1 is 3.6x10 to the minus 17th power cm3s, approximately eight times larger than a value reported previously in the literature.
- Geology, Geochemistry and Mineralogy
- Lasers and Masers