Four-photon mixing in ghost fiber spectroscopy

By | 15.09.2024

N. S. Starshinov, A. V. Belinsky, A. B. Fedotov

  • Faculty of Physics, Lomonosov Moscow State University, 119991, Moscow, Russia
  • Russian Quantum Center, Skolkovo, 121353, Moscow, Russia
Abstract: We report an experimental implementation of linear absorption spectroscopy using a fiber source of frequency-correlated photon pairs. The object under study is illuminated by a signal beam of a photon pair entangled in frequency. Due to the tight correlation of entangled photons, the absorption spectrum of the object can be measured from the idler beam, counting coincidences in both channels. The main advantages of ghost optics are analyzed, including significant noise reduction due to detecting only paired coincidences and cutting off all single background photons, as well as the potential sensitivity of studying samples, which is especially important when working with biological objects.
Keywords: quantum optics, ghost optics, entangled states, four-photon mixing.
The work was supported by the Russian Science Foundation [grant no. 22-12-00149 (experimental implementation of linear absorption spectroscopy using a fiber source of frequency-correlated photon pairs) and grant no. 21-12-00155 (calculation of the photon count rate and assessment of the sensitivity of the method)].
Received: 07.08.2023
Revised: 08.10.2023
Accepted: 08.10.2023