Tampere University of Technology

TUTCRIS Research Portal

Influence of pump coherence on the quantum properties of spontaneous parametric down-conversion

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Article number084001
Number of pages8
JournalPhysica Scripta
Issue number8
Publication statusPublished - Aug 2018
Externally publishedYes
Publication typeA1 Journal article-refereed


The correlation properties of the pump field in spontaneous parametric down-conversion are crucial in determining the degree of entanglement of generated signal and idler photons. We find theoretically that continuous-variable entanglement of the transverse positions and momenta of these photons can be achieved only if the coherence of the pump beam is sufficiently high. The positions of signal and idler photons are found to be correlated, even for an incoherent pump. However, the momenta of the signal and idler photons are not anti-correlated, even though transverse momentum is conserved.


  • entaglement, patrametric down-conversion, partially coherent beam, Gaussian Schell-model beam, BELL-INEQUALITY, TIME