Quantum fluctuations and noise in interferometry and photodetection: applications in optical sensing and micromanipulation

Accurate optical sensing and micromanipulation requires sensitive measurements of the position, orientation, and dynamics of small particles--and sometimes even large objects--under consideration. The signals acquired in the process, including those needed for the feedback control of these particles and objects, are inevitably contaminated by quantum fluctuations and noise that accompany the physical processes of optical interference and photodetection (or photon counting). This paper explores the origins of signal fluctuation and quantum noise that are inevitably associated with such sensitive measurements.