Demonstration of Backward-wave Parametric Down-Conversion

Ultrabright sources of temporally long and spectrally narrow photons are essential for efficient light-matter interaction at the single-photon level. To achieve high brightness, parametric down-conversion of the backward-wave type was proposed for single-mode generation of long biphotons [1]. In this talk I will describe the demonstration of backward-wave parametric down-conversion in a nonlinear crystal, of which the time-energy entanglement was characterized by the Franson interference. I will also discuss the possibility of realizing a miniature ultrabright biphoton source.\\[4pt] [1] C.-S. Chuu and S. E. Harris, Phys. Rev. A 83, 061803(R) (2011)