Dispersion spreading of polarization-entangled states of light and two-photon interference

• Main Authors: Brida, G, Chekhova, M. V, Genovese, M, Krivitsky, L. A
• Format: Journal Article
• Language: English
• Published: 20-07-2006
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.quant-ph/0607137

Phys. Rev. A 75, 015801 (2007) We study the interference structure of the second-order intensity correlation
function for polarization-entangled two-photon light obtained from type-II
collinear frequency-degenerate spontaneous parametric down-conversion (SPDC).
The structure is visualised due to the spreading of the two-photon amplitude as
two-photon light propagates through optical fibre with group-velocity
dispersion (GVD). Because of the spreading, polarization-entangled Bell states
can be obtained without any birefringence compensation at the output of the
nonlinear crystal; instead, proper time selection of the intensity correlation
function is required. A birefringent material inserted at the output of the
nonlinear crystal (either reducing the initial o-e delay between the oppositely
polarized twin photons or increasing this delay) leads to a more complicated
interference structure of the correlation function.