Patent ID: 7359514

Claim:
A system for generating narrow-band single photons, comprising: a pump light source that generates pump light; a non-linear medium arranged to receive the pump light and generate time-energy entangled signal and idler photons having respective first and second wavelengths and corresponding first and second spectral bandwidths; a wavelength-selective member arranged to receive the signal and idler photons and direct the photons along respective first and second optical paths; a narrow-band optical filter having a select spectral bandwidth and arranged along the second optical path so as to filter the idler photons so that only narrow-band idler photons pass therethrough; a single-photon detector arranged downstream of the optical filter and adapted to detect each narrow-band idler photon that passes through the optical filter; and wherein said filtering and detecting of the narrow-band idler photons causes a corresponding amount of non-local filtering of corresponding signal photons via said time-energy entanglement, so as to create narrow-band signal photons.