Science / Technology - Colloquium
Tuesday, April 25, 2006
9:00 AM-10:00 AM
Olin Hall
107
The McCumber theory allows optical emission cross section spectra to be determined from measured absorption spectra, and vice versa. The present work is a detailed study of the range of validity of the McCumber theory, focusing particularly on those aspects that most critically affect its applicability to transitions of rare earth ions in glasses. When the various possible sources of systematic error are properly accounted for, we find in all cases an excellent agreement between the calculated and the measured cross section spectra. This suggests that at room temperature, the McCumber theory is not limited to crystalline hosts, as has been asserted in the literature, but describes quite well the reciprocity between emission and absorption for the broader transitions of rare earths in glassy hosts. At lower temperatures, however, discrepancies are observed, and our results suggest that the McCumber theory must be used with caution for temperatures below 200 K.
Cost: free
Sponsored by: WPI Physics Department, Dr. Rafael Garcia
Suggested Audiences: College
E-mail:
garcia@wpi.edu
Phone: 508-831-5322
Last Modified: April 18, 2006 at 3:06 PM
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