Investigation of loss processes of Tm and Tm,Ho in YAGThe loss of excitation from various manifolds of Tm and Tm,Ho in YAG as a function of temperature and concentration is studied. Two probable loss mechanisms - a Tm up-conversion and a Ho up-conversion - are identified. A 785-nm CW diode laser with 400-nW peak power was focused to a small spot on the sample. The emission from the sample observed at 90 deg was monitored through a monochromator with slits open to 3 mm. Intensity of emission was measured by varying the power of the excitation source using a set of neutral density filters. Power is reported as the percentage of the peak power, and the intensity curves were normalized below 20 percent of transmission. The fact that there is emission above the pump energy indicates an up-conversion from excited manifolds. Nonlinear changes in the intensity of the emission from the Tm 3F4 manifold with the pump power reveals a loss of excitation from this manifold. The linear dependence of the 5I7 manifold emission with pump power at low Tm and high Ho concentrations and the gain of energy in the 5I6 manifold of Ho indicate that the 5I7 manifold loss is due to the coupling of Tm and Ho ions.
Document ID
19920068637
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Armagan, G. (NASA Langley Research Center Hampton, VA, United States)
Buoncristiani, A. M. (Christopher Newport College Newport News, VA, United States)
Bair, C. H. (NASA Langley Research Center Hampton, VA, United States)
Inge, A. T. (NASA Langley Research Center Hampton, VA, United States)
Hess, R. V. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1991
Subject Category
Lasers And Masers
Meeting Information
Meeting: Topical Meeting of the OSA Proceedings on Advanced Solid-State Lasers