Prototype Interferometry in the Era of Gravitational Wave Astronomy

Abstract

Since the first direct detection of gravitational wave signals from the coalescence of a pair of stella-mass black holes on 14 September 2015, a global network of terrestrial interferometric detectors, with kilometer-scale arms, have opened a new window through which the astrophysical universe can be probed. This success was the result of decades of exploratory work done on smaller-scale prototype interferometers. Even though the detection of astrophysical gravitational wave signals has become almost a routine event, prototype interferometers remain an essential tool in developing technologies for future generations of kilometer-scale detectors. They are unique in that they are large enough to probe physics that cannot be easily investigated on the table-top, but have no obligation to function as an observatory, and so can be readily modified for a wide variety of experiments. This thesis focuses on one direction in which prototype interferometry can be taken, serving as a testbed for testing the laws of quantum mechanics at the macroscopic scale. While this is in itself an interesting experimental program, it can make a direct contribution to the field of gravitational wave astronomy since future generations of terrestrial detectors are expected to be limited in their sensitivity due to measurement limits set by the Heisenberg uncertainty principle. Techniques to evade these limits can be demonstrated on a prototype interferometer, before embarking on an expensive program to implement them at the scale necessary for kilometer-scale observatories.