Phase-sensitive detection and the back-action evasion of amplifier force noise
Abstract
Limitations on the sensitivity for detecting a weak classical force acting on a harmonic oscillator are imposed by the quantum mechanical properties associated with a standard amplitude-and-phase measurement and, classically, by the back reaction noise associated with the finite noise temperature of the amplifier used to process the measurement. These are known as the standard quantum limit and the standard amplifier limit, respectively. The theoretical motivation behind the quest to circumvent these limits is presented, and a single-transducer back-action evading measurement scheme designed to perform a phase-sensitive coupling to the oscillator is examined, with the concomitant circumvention of the standard amplifier limit via the squeezing of amplifier back reaction noise. The applicability of squeezing in the detection of gravitational radiation is explored via the dependence of detection sensitivity on the physical temperature and quality factor of the resonant-bar gravitational radiation antenna, on the noise temperature of the amplifier, and on the squeezing factor of the back-action evading measurement; the success of back-action evasion in improving upon the optimum amplitude-and-phase detection sensitivities depends critically upon these parameters.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1985
- Bibcode:
- 1985PhDT........52S
- Keywords:
-
- Harmonic Oscillators;
- Noise Temperature;
- Quantum Mechanics;
- Sensitivity;
- Weak Interactions (Field Theory);
- Antennas;
- Detection;
- Gravitational Waves;
- Squeezed States (Quantum Theory);
- Communications and Radar