Tunable Microwave Cavities for Macroscopic Cavity Optomechanics
- Author(s): Pate, Jacob Michael
- Advisor(s): Sharping, Jay E
- et al.
This thesis begins with the introduction of optomechanics, the study of the interaction between light (photons) and mechanical oscillations (phonons) using bulk 3-D cavities. The description of 3-D microwave cavities is introduced as the boundary of the electromagnetic field and the mathematics are developed for the interaction between the electromagnetic field and a fluctuating boundary (mechanical oscillator). This work was established in pursuit of observing optomechanical effects within macroscopic 3-D cavity systems.
Three main microwave 3-D cavity geometries were used for this work: cylindrical, re-entrant, and coaxial quarter-wave (λ/4) cavities. A large number of cavities were made by the author in a machine shop in an attempt to develop strongly-coupled optomechanical systems. The pursuit of this goal led to the first observation of strain engineering, or dissipation dilution, via the thermal Casimir effect and its exciting potential applications.
The noteworthy projects that saw success in this work were the development of tunable, superconducting microwave cavities using a lossless, non-contacting fashion in addition to the ground-up progression of re-entrant cavities that led to the first observation of the thermal Casimir spring and dilution effect at room temperature. The outcome of this work opens the doorway for the development of “in situ” arbitrary, topological resonators with the added benefit of an increased mechanical quality factor Qm due to heightened strain.