Generation of single photons with a controllable waveform in the process of spontaneous pulse-pumped parametric downconversion

The scheme for a single-photon source based on the effects of spontaneous parametric downconversion and slow light is developed, which makes it possible to control the waveform of a single-photon impulse by that of the pump pulse. It is shown that the suggested scheme can prevent additional losses introduced by amplitude modulators thereby achieving the highest possible efficiency of the conditional preparation of single photons.