Absorption Spectroscopy of Rubidium in an Alkali Metal Dispenser Cell and Bleached Wave Analysis
Abstract
An absorption spectrum of a rubidium alkali metal dispenser (AMD) cell was obtained in order to determine the system s suitability for use in a diode pumped alkali laser (DPAL) and use in high-temperature spectroscopic studies. The AMD produced a concentration of 3.65 0.16 1010 cm-3, which is in the ideal range for Beer s Law region absorption spectroscopy, but too low to make a high-power DPAL in a 10 cm cell with a poor Q resonator. Before AMDs can be used to determine pressure broadening and shifting coefficients, issues concerning contamination and producing rubidium vapor at pressure must be resolved. A separate portion of this study focused on a sealed rubidium Pyrex cell with neon buffer gas. A continuous wave titanium sapphire beam was focused into the cell with various lenses to maximize pump intensity through the cell. Images were taken of the side fluorescence of the cell to determine the bleached regions. The total horizontal propagation of the bleached region for each image was proportional to the pump laser power and the inverse of the rubidium vapor density. Disparity between the bleached volume estimated from the beam parameters and the theoretical bleached volume suggested the beam intensity had a strong radial dependence. When the pump wavelength was changed, visible side fluorescence occurred in regions where the laser intensity was at least 0.125 times the saturation intensity and therefore not in the regions where the decay was determined by Beer s Law.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 26, 2015
- Accession Number
- ADA616797
Entities
People
- James M. Rosenthal
Organizations
- Air Force Institute of Technology