All ETDs from UAB

Advisory Committee Chair

Clayton E Simien

Advisory Committee Members

Jianing Han

Sergey B Mirov

James C Patterson

Robert D Mohr

Document Type

Thesis

Date of Award

2020

Degree Name by School

Master of Science (MS) College of Arts and Sciences

Abstract

Ultra-cold samples of atomic Gadolinium (Gd) are of interest for developing novel time-frequency standards, investigating strongly correlated Rydberg atoms, and state-of-the-art nanoscale applications. In this work, I present previous work in which the hyperfine coefficients and isotope shifts were measured for the first time in spin-forbidden transitions of atomic Gd, which are of interest for experiments investigating dipolar physics. The spin forbidden transitions are found to be too weak for use as laser cooling lines but would prove useful for developing a novel optical frequency standard due to the suppression of background blackbody radiation shifts and laser frequency shifts from atomic resonances. The measured isotope shifts would prove very useful for more efficient laser isotope separation techniques for the 157Gd isotope, which is used in medical and nuclear industry applications. The 9D2→9P3 (368 nm) and 9D6→9F7 (423 nm) transitions in atomic Gd were chosen as possible laser cooling candidates due to their transition probabilities and linewidths. In this work I investigate the excited state populations through a density matrix formalism by solving the density matrix equations for a two and three level system for the 423 nm and 368 nm transitions respectively for the bosonic isotopes. I then show the laser cooling force for the 423 nm transition and calculate the laser cooling parameters for both the 368 nm and 423 nm transitions. The 368 nm transition demonstrated population trapping in the intermediate ground state of the three-level system, which would require an additional laser to form the laser cooling transition. This multi-photon scheme will be investigated in future work along with the more detailed treatment of the density matrix equations of the fermionic isotopes using a more robust computational method. The 368 nm transition has some spectroscopic data, which would be utilized for laser cooling, but the 423 nm transition has virtually none. I also propose a future experiment in Appendix A to measure the spectroscopic features of the stable isotopes of Gd for these transitions in order to produce ultra-cold atomic samples for the applications mentioned above.

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