Study of processes with single photons

Several information processing protocols are based on states of light that correspond to single photons (non-classical states). Obtaining these states in the laboratory is not easy. However, we show that it is possible to explore single-photon processes without having these states using phase-averaged coherent states (classical states) instead. As an illustration of this possibility we perform tomographic reconstruction of the Wigner function of the single-photon state. This function shows obvious non-classical characteristics such as being negative around the origin [Val17][Auy19].

[Val17] “Probing single-photon state tomography using phase-randomized coherent states”. P. Valente and A. Lezama, J. Opt. Soc. Am. B 34, 924-929 (2017).

[Auy19] “Full statistics of ideal homodyne detection using real (noisy) local oscillator“, A. Auyuanet, E. Benech, H. Failache and A. Lezama. Journal of the Optical Society of America B, 36, 140 (2019).

Estudio de procesos con fotones individuales

Función de Wigner del estado de un fotón reconstruida a partir de estados coherentes promediados en fase.