Quantum nondemolition measurement of light intensity fluctuations in an optomechanical experiment
A. Pontin (University of Florence, Istituto Nazionale di Fisica Nucleare - Sezione di Firenze)
M Bonaldi (Trento Institute for Fundamental Physics and Application, Institute of Materials for Electronics and Magnetism, Nanoscience-Trento-FBK Division)
Antonio Borrielli (Trento Institute for Fundamental Physics and Application, Institute of Materials for Electronics and Magnetism, Nanoscience-Trento-FBK Division)
L. Marconi (Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche)
F. Marino (Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Istituto Nazionale di Fisica Nucleare - Sezione di Firenze)
G. Pandraud (TU Delft - EKL Processing)
G.A. Prodi (Trento Institute for Fundamental Physics and Application, Università di Trento)
Pasqualina Maria Sarro (TU Delft - Electronic Components, Technology and Materials)
E Serra (TU Delft - Electronic Components, Technology and Materials, Trento Institute for Fundamental Physics and Application)
F. Marin (Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Istituto Nazionale di Fisica Nucleare - Sezione di Firenze, European Laboratory for Non-linear Spectroscopy (LENS), University of Florence)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Summary form only given. According to quantum mechanics, there exists a class of observables for which is possible to confine the perturbation produced by a continuous measurement to the conjugate variable. Therefore, it is possible to devise experimental schemes that allow estimating the observed variable with arbitrary accuracy, or preparing it in a well-known state. Such schemes are referred to as quantum non-demolition measurements (QND). Among these observables there is the amplitude of the light field. Indeed, it is possible to exploit a movable mirror to implement a QND scheme [1]. Intensity fluctuations of an optical field impinging on it are not affected by the interaction. However, the movable mirror is excited by the associated radiation pressure. This, in turn, affects the phase of the field.We have performed an optomechanical experiment, based on a Fabry-Pérot cavity in which the end mirror is a high Q micro-mechanical device [2], where we have simultaneously measured intensity fluctuations of the field reflected by the cavity and the mirror motion imprinted in the phase fluctuations. By exploiting the correlations between these variables, we demonstrate a reduced uncertainty on intensity fluctuations actually achieving a sub-shot noise level.