Speaker
Description
Two-photon interferometry (TPI), the very investigation of which historically led to the development of the modern description of the coherence of light as well as to the foundation of quantum optics [1,2,3], has evolved towards a booming research field whose applications span from quantum cryptography and computing [4] to biosensing [5], astrometry and telescopy [6], imaging and tomography [7,8], metrology and fundamental physics [9]. Photon “bunching”, a direct consequence of the bosonic nature of light and one of the main features of TPI, is the working principle behind the production of optical N00N states, candidates of strong interest for quantum communications and computing [10] as well as for the collective technologies that are now referred to as “quantum internet”. Intriguingly, TPI can be investigated with many different probe states, from entangled pairs on two or more degrees of freedom to coherent and thermal light, proving its remarkable capability to adapt to a wide variety of sources and needs. In this scientific and technological landscape, even the intrinsic boundary imposed to the TPI operating range by the requirement of total or at least partial indistinguishability of the optical paths has ultimately come under scrutiny [11,12]. In this talk, an innovative approach to TPI will be presented [13,14], showcasing how conjugate-variable interrogation of a TPI system leads to the emergence of a rich dynamics characterized by broader operative range and multiplexing capabilities, both highly desirable qualities for communication and cryptography protocols.
References
[1] Brown, R. Hanbury, and Richard Q. Twiss, “Correlation between photons in two coherent beams of light,” Nature 177, 27–29 (1956).
[2] Glauber, Roy J., “The quantum theory of optical coherence,” Physical Review 130, 2529 (1963).
[3] Hong, Chong-Ki, Zhe-Yu Ou, and Leonard Mandel, “Measurement of subpicosecond time intervals between two photons by interference,” Physical Review Letters 59, 2044 (1987).
[4] Ekert, Artur K., et al., “Practical quantum cryptography based on two-photon interferometry,” Physical Review Letters 69, 1293 (1992).
[5] Lotfipour, Hoda, et al., “Application of quantum imaging in biology,” Biomedical Optics Express 16, 3349–3377 (2025).
[6] Crawford, Jesse, et al., “Towards quantum telescopes: demonstration of a two-photon interferometer for precision astrometry,” Optics Express 31, 44246–44258 (2023).
[7] Nasr, Magued B., et al., “Demonstration of dispersion-canceled quantum-optical coherence tomography,” Physical Review Letters 91, 083601 (2003).
[8] Yepiz-Graciano, Pablo, et al., “Spectrally resolved Hong–Ou–Mandel interferometry for quantum-optical coherence tomography,” Photonics Research 8, 1023–1034 (2020).
[9] Brady, Anthony J., and Stav Haldar, “Frame dragging and the Hong–Ou–Mandel dip: gravitational effects in multiphoton interference,” Physical Review Research 3, 023024 (2021).
[10] Grün, Daniel S., et al., “Protocol designs for NOON states,” Communications Physics 5, 36 (2022).
[11] Triggiani, Danilo, Giorgos Psaroudis, and Vincenzo Tamma, “Ultimate quantum sensitivity in the estimation of the delay between two interfering photons through frequency-resolving sampling,” Physical Review Applied 19, 044068 (2023).
[12] Triggiani, Danilo, and Vincenzo Tamma, “Estimation with ultimate quantum precision of the transverse displacement between two photons via two-photon interference sampling measurements,” Physical Review Letters 132, 180802 (2024).
[13] Di Lena, Francesco, et al., “High-Precision Measurement of Time Delay with
| Sessions | Foundational studies |
|---|---|
| Invited | No |