Abstract

I briefly review second order or two-photon correlations starting from the Hanbury Brown-Twiss correlations to its modern versions in quantum optics studies. With this background, I address some foundational issues in the physics of quantum correlations and quantum entanglement and argue in favour of the validity of Einstein locality. Understanding entanglement from this perspective has applications in quantum information theory, especially in gaining intuition about different measures of entanglement and its time evolution. I discuss how ideas on photon correlations applied to squeezing fluctuations in coherent light have become important in metrology.

© 2012 OSA