This book presents a direct measurement of quantum back action, or radiation pressure noise, on a macroscopic object at room temperature across a broad bandwidth in the audio range. This noise source was predicted to be a limitation for gravitational wave interferometers in the 1980s, but it has evaded direct characterization in the gravitational wave community due to the inherent difficult of reducing thermal fluctuations below the quantum back action level. This back action noise is a potential limitation in Advanced LIGO and Advanced Virgo, and Cripe's experiment has provided a platform for the demonstration of quantum measurement techniques that will allow quantum radiation pressure noise to be reduced in these detectors. The experimental techniques Cripe developed for this purpose are also applicable to any continuous measurement operating near the quantum limit, and could lead to the possibility of observing non-classical behavior of macroscopic objects.
Jonathan Cripe graduated from DePauw University with a B.A. and majored in physics and mathematics. After graduation, he studied for one year at the Albert Einstein Institute in Hannover, Germany, before starting his Ph.D. at Louisiana State University. While at LSU, Jonathan was a member of the LIGO collaboration and worked with Professor Thomas Corbitt on investigating quantum technologies for improving future generations of gravitational wave detectors. One of the highlights of his scientific career was participating in the first direct detection of gravitational waves. Jonathan is currently a physicist at the National Institute of Standards and Technology where he is applying his experience with radiation pressure to create reference devices for measuring nanonewton level forces.
Gravitational Waves and Gravitational Wave Detectors.- Optical Springs.- Cantilever Micro-Mirror and Optomechanical Cavity Design.- Radiation-Pressure-Mediated Control of an Optomechanical Cavity.- Observation of an Optical Spring from a Beamsplitter.- Broadband Measurement of Quantum Radiation Pressure Noise at Room Temperature.- Quantum Radiation Pressure Noise Reduction and Evasion.- Future Work and Conclusion.