Blackbody pumped carbon dioxide laser
A proof of concept experiment was carried out to demonstrate the feasibility of using blackbody radiation to pump a gas laser. Building on earlier experiments in which optical gain was measured in a CO/sub 2/ laser mixture exposed to blackbody radiation at a temperature of 1500/sup 0/K, continuous wave oscillation of CO/sub 2/ was achieved, for the first time, using radiation from a blackbody cavity as the pump source. This was made possible by actively cooling the laser mixture as it was exposed to the radiation field of an electrically heated oven. Output power measurements are presented from a series of experiments using mixtures of CO/sub 2/, He, and Ar. Maximum output power was obtained with a 20%CO/sub 2/-15%He-65%Ar mixture at pressures around 6 to 10 Torr. The output power was found to vary greatly with the gas temperature and the blackbody temperature. By varying these parameters, output powers up to 8 mW have been achieved. The effectsof the buffer gas are also shown to be important. Based on the experimental results, it is believed that the buffer gas is needed to inhibit diffusion of the excited species out of the laser mode volume. This diffusion leads to deactivation at the walls. Adding more CO/sub 2/ results in a decrease in output power, indicating that the gas has a finite optical depth and the mode volume is not pumped if too much CO/sub 2/ is present. A model that incorporates these effects is presented. The predicted small signal gains and powers based on this model adequately match the trends observed experimentally.
- OSTI ID:
- 5785260
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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