@inproceedings{8e6aa25e85d14bb3bd58a0bb5c166a93,
title = "Toward Vibration Measurement via Frequency-Entangled Two-Photon Interferometry",
abstract = "We present progress toward measuring nanometer-scale vibrations via a frequency-entangled two-photon interferometer. Unlike classical interference, two-photon – or Hong-Ou-Mandel – interference allows for optical metrology with resilience against imbalanced loss, dispersion, and optical background. However, the resolution of traditional degenerate frequency two-photon interference is limited by the photons{\textquoteright} bandwidths, requiring large bandwidths or long integration times to achieve nanometer-scale resolution. We have implemented a two-photon interferometer utilizing highly non-degenerate frequency-entangled photon pairs at 810 nm and 1550 nm, drastically increasing measurement sensitivity while retaining the advantages of two-photon interference. This enhancement comes via a beat note with frequency proportional to the photon detuning of 177 THz. The resulting measurement saturates the quantum Cram{\'e}r-Rao bound, maximizing the information extracted per photon. We have demonstrated a measurement resolution of 2.3 nm with fewer than 18,000 detected photon pairs, orders of magnitude better than previous results. By reflecting one photon from the pair off a target surface, we may use our system to study small-scale vibrations.",
keywords = "Frequency entanglement, precision sensing, two-photon interference",
author = "Johnson, {Spencer J.} and Lualdi, {Colin P.} and Conrad, {Andrew P.} and Arnold, {Nathan T.} and Michael Vayninger and Kwiat, {Paul G.}",
note = "Publisher Copyright: {\textcopyright} 2023 SPIE.; Quantum Sensing, Imaging, and Precision Metrology 2023 ; Conference date: 28-01-2023 Through 02-02-2023",
year = "2023",
doi = "10.1117/12.2650820",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Jacob Scheuer and Shahriar, {Selim M.}",
booktitle = "Quantum Sensing, Imaging, and Precision Metrology",
}