Physics & Astronomy ETDs

Spring 3-28-2019

Abstract

Atomic clocks provide one of the fundamental building blocks upon which modern telecommunications systems are constructed. Since the invention of the frequency comb in the early 2000s, laboratory frequency standards have quickly outpaced their compact counterparts. Compact clocks, however, have continued to leverage microwave transitions not yet exploring the advantages of an optical atomic clock. With the recent development of robust frequency combs compact optical clocks can now be realized. In this dissertation two atomic species are investigated for a compact atomic frequency standards. Both of these clocks are in different development stages but offer unique advantages. The optical rubidium atomic frequency standard relies on a two-photon transition in rubidium. This dissertation details the design necessary to achieve best clock stabilities to date leveraging this two-photon transition. Calculations and measurements of required environmental instabilities to reach stabilities of $1\times 10^{-15}$ at one day are included. The hardest environmental parameters to suppress are the self collisional shift and the ac-Stark shift. A new approach to reduce ac-Stark shift is discussed as well as a robust thermal design which achieved necessary temperature stabilities. Calcium provides a much narrower transition then the two-photon rubidium for which to build a clock. A calcium vapor cell could revolutionize experimentation with this species. This dissertation describes a first ever closed calcium vapor cell. I also describe a method for continuous operation of this vapor cell without replenishing calcium or cleaning the optical windows. The optical rubidium atomic frequency standard has shown fractional frequency instabilities of $4\times 10^{-13}/\sqrt{\tau(s)}$ for $\tau$ from 1 to 10,000 seconds, with potential to achieve instabilities of less then $1\times 10^{-13}$ at one second and less then $4\times 10^{-15}$ at one day. The calcium clock is still in vapor cell development stages, showing some promise for future fully realized calcium clock based on vapor cell technologies.

Physics

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

Francisco Elohim Becerra-Chavez

Ivan Deutsch

Nathan Lemke

Andrew Metcalf

English

Keywords

Atomic Optical Clocks, Timing and Frequency Standards, Metrology, Optoelectronics, Photonics

Dissertation

COinS