PhD Proposal: Thomas Smith
TITLE: Turbulence-free Interferometry and its Application to Gravitational Wave Detection
ABSTRACT: Recently our research group has developed a mechanism for an interferometer that is insensitive to any rapid fluctuations of the length or phase along the optical paths of the interferometer. These fluctuations, also known as optical turbulence, are due to rapid changes in index of refraction typically caused by changes in density or composition of the light-propagating medium. Classic interferometers are negatively affected by such conditions, making the most sensitive interferometers unusable in open air. A prime example of this are the interferometers used for gravitational wave detection. The interferometer used at the Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two perpendicular arms for the light to propagate (fundamentally the same as a Michelson interferometer). To avoid the negative effects of optical turbulence present in the atmosphere, these arms are contained in high-cost vacuum chambers. With an interferometer that is insensitive to turbulence, a vacuum would not be needed to conduct these sensitive measurements.
Here I propose a theoretical and experimental study on the physics of this turbulence-free mechanism and its application toward developing a turbulence-free interferometer gravitational wave detector. Demonstrated recently at UMBC through a turbulence-free double-slit interferometer, this mechanism will be adapted to other types of interferometers in an attempt to find the best candidate for gravitational wave detection. While a turbulence-free Michelson interferometer would seem like the next logical step, we have reason to believe a turbulence-free Sagnac interferometer is a superior choice. An experimental demonstration of the turbulence-free nature of such an interferometer would provide a step toward inexpensive gravitational wave detectors and the benefits that they would provide.