In the early experiments on optical pumping and coherent population trapping (''dark resonances'') increasing buffer gas pressure enhances the effect. In our recent lasing-without-inversion experiments, based on population trapping, we find the opposite behavior, namely, decreasing atomic coherence with increasing buffer gas pressure. We provide a theoretical explanation of this result in agreement with experiment.
Scopus Subject Areas
- Atomic and Molecular Physics, and Optics