We propose and experimentally realize a new scheme for universal phase-insensitive optical amplification. The presented scheme relies only on linear optics and homodyne detection, thus circumventing the need for nonlinear interaction between a pump field and the signal field. The amplifier demonstrates near optimal quantum noise limited performance for a wide range of amplification factors.
@article{arxiv.quant-ph/0603119,
title = {Universal optical amplification without nonlinearity},
author = {V. Josse and M. Sabuncu and N. J. Cerf and G. Leuchs and U. L. Andersen},
journal= {arXiv preprint arXiv:quant-ph/0603119},
year = {2009}
}