We propose and analyze a new time-domain method for subcycle metrology of quantum electric fields using a combination of a 3rd order nonlinear optical process and homodyne detection with a local oscillator (LO) field. The new method enables isolation of intrinsically weak quantum noise contribution by subtraction of the shot noise of the LO on a pulse-by-pulse basis. Together with the centro-symmetric character of the nonlinearity, our method unlocks novel opportunities toward terahertz and mid-infrared quantum field metrologies.
@article{arxiv.2201.10487,
title = {Self-referenced subcycle metrology of quantum fields},
author = {Sinan Gündoğdu and Stéphane Virally and Marco Scaglia and Denis V. Seletskiy and Andrey S. Moskalenko},
journal= {arXiv preprint arXiv:2201.10487},
year = {2023}
}