Squeezing and feedback
Abstract
Electro-optical feedback has many features in common with optical nonlinearities and hence is relevant to the generation of squeezing. First, I discuss theoretical and experimental results for traveling-wave feedback, emphasizing how the ``in-loop'' squeezing (also known as ``squashing'') differs from free squeezing. Although such feedback, based on ordinary (demolition) photodetection cannot create free squeezing, it can be used to manipulate it. Then I treat feedback based on nonlinear quantum optical measurements (of which non-demolition measurements are one example). These {\em are} able to produce free squeezing, as shown in a number of experiments. Following that I discuss theories showing that intracavity squeezing can be increased using ordinary feedback, and produced using QND-based feedback. Finally, I return to ``squashed'' fields and present recent results showing that the reduced in-loop fluctuations can suppress atomic decay in a manner analogous to the effect for squeezed fields.
Cite
@article{arxiv.quant-ph/0112128,
title = {Squeezing and feedback},
author = {H. M. Wiseman},
journal= {arXiv preprint arXiv:quant-ph/0112128},
year = {2007}
}
Comments
54 pages, 4 figures. Accepted (in 1999) as an invited chapter in "Quantum Squeezing", a Springer volume edited by P.D. Drummond and Z. Ficek. This is the final, updated, version supposedly to be published in November 2003