Upconversion-pumped 2. 8--2. 9-. mu. m lasing of Er sup 3+ ion in garnets

Journal Article · Sun Dec 15 04:00:00 EST 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.349767· OSTI ID:6256134

Pollack, S A ^[1]; Chang, D B ^[2]; Birnbaum, M ^[3]; Kokta, M ^[4]

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1. Optitron, Inc., 23206 S. Normandie Ave., Torrance, California (USA)
2. Hughes Aircraft Co., TSGG, P. O. Box 10011, Manhattan Beach, California (USA)
3. Center for Laser Studies, USC, University Park, Los Angeles, California (USA)
4. Union Carbide Corporation, Washougal, Washington (USA)

Upconversion-pumped lasing characteristics near 3 {mu}m on the {sup 4}{ital I}{sub 11/2}-{sup 4}{ital I}{sub 13/2} transition of the Er{sup 3+} ion in Er:YSGG (erbium-yttrium-scandium-gallium garnet) and Er:YAG (erbium-yttrium-aluminum-garnet), laser state spectroscopy, and population kinetics, are the main subjects discussed. The wide difference in lasing patterns of both garnets can be attributed to the difference in population inversion kinetics which was studied by analyzing the rise and decay of fluorescence starting from the laser states. It is shown that the effective decay times, {tau}{sub 1} and {tau}{sub 2} of the lower and upper laser states, are changed during lasing by the nonlinear energy-transfer processes such that the resulting ratio becomes {tau}{sub 1}/{tau}{sub 2}{lt}1. In Er:YSGG this condition is established during the declining phase of the {sup 4}{ital I}{sub 11/2} population, whereas in Er:YAG it occurs only for a short time during the rising phase. Consequently Er:YAG lases in a self-terminating pulsed mode. The role of various energy-transfer processes in the upconversion-pumped population inversion kinetics is discussed and analyzed. It is experimentally shown that the lower {sup 4}{ital I}{sub 13/2} laser state in both garnets is depopulated by the cooperative energy summing due to the di- and tri-ionic interactions. Because of these interactions, the {sup 4}{ital I}{sub 11/2} and {sup 4}{ital S}{sub 3/2} states are populated with ensuing fluorescence from these states at 980 and 550 nm, respectively. The indication that the latter state is populated directly by the tri-ionic interaction, rather than via the former state by two sequential ion-pair interactions, follows from the experimental fact that the 550-nm fluorescence rises faster and reaches its maximum sooner than the 980-nm fluorescence.

• OSTI ID: 6256134
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 70:12; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHARGED PARTICLES
EMISSION SPECTRA
ERBIUM COMPOUNDS
ERBIUM IONS
ERBIUM OXIDES
FLUORESCENCE
GALLIUM COMPOUNDS
GALLIUM OXIDES
GARNETS
IONS
LASERS
LUMINESCENCE
MINERALS
NUMERICAL SOLUTION
OXIDES
OXYGEN COMPOUNDS
POPULATION INVERSION
RARE EARTH COMPOUNDS
SCANDIUM COMPOUNDS
SCANDIUM OXIDES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SOLID STATE LASERS
SPECTRA
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES