Building a modern micromaser : atoms and cavities

• Main Author: Sanguinetti, Bruno
• Published: University of Leeds 2009
• Subjects: 621.381336
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505074

The One Atom Maser, or Micromaser is a cavity Q.E.D. experiment. consisting of a high-Q superconducting microwave cavity which interacts with a sequence of single 2-level Rydberg atoms. Thanks to the simplicity with which it can be treated theoretically and thanks to its fundamental nature it has generated much interest. Its implementation however is technically complex. In this thesis I will show how a variety of new techniques can be used to make this experiment more accessible and scalable. In particular I develop a 3-step laser excitation system for Rubidium Rydberg states, which I present together with the most accurate Rydberg spectroscopy to date of Rubidium P states with principal quantum number 36 to 63, from which quantum defects and an accurate value of the ionisation energy of Rubidium is derived. Work on locking multiple lasers to a single frequency comb, thus performing accurate multi-step spectroscopy is presented. A motor able to produce a 10 N force and 5 em of travel and operating at cryogenic temperatures is described as well as the practical usage of the first single-chamber cryogen-free dilution refrigerator. I discuss the details of cavity design and manufacturing and present new results on the optimal geometry of a Fabry-Perot resonator in the near-field limit. I also discuss how an alkali metal dispenser beam source was used in the experiment.