Quantum-enhanced optical phase tracking
Quantum Physics
2012-09-24 v1
Abstract
Tracking a randomly varying optical phase is a key task in metrology, with applications in optical communication. The best precision for optical phase tracking has till now been limited by the quantum vacuum fluctuations of coherent light. Here we surpass this coherent-state limit by using a continuous-wave beam in a phase-squeezed quantum state. Unlike in previous squeezing-enhanced metrology, restricted to phases with very small variation, the best tracking precision (for a fixed light intensity) is achieved for a finite degree of squeezing, due to Heisenberg's uncertainty principle. By optimizing the squeezing we track the phase with a mean square error 15 \pm 4 % below the coherent-state limit.
Cite
@article{arxiv.1209.4716,
title = {Quantum-enhanced optical phase tracking},
author = {Hidehiro Yonezawa and Daisuke Nakane and Trevor A. Wheatley and Kohjiro Iwasawa and Shuntaro Takeda and Hajime Arao and Kentaro Ohki and Koji Tsumura and Dominic W. Berry and Timothy C. Ralph and Howard M. Wiseman and Elanor H. Huntington and Akira Furusawa},
journal= {arXiv preprint arXiv:1209.4716},
year = {2012}
}
Comments
33 pages, 12 fugres