  We propose and experimentally demonstrate a novel approach to a heralded
single photon source based on spectral multiplexing (SMUX) and
feed-forward-based spectral manipulation of photons created by means of
spontaneous parametric down-conversion in a periodically-poled LiNbO3 crystal.
As a proof-of-principle, we show that our 3-mode SMUX increases the heralded
single-photon rate compared to that of the individual modes without
compromising the quality of the emitted single-photons. We project that by
adding further modes, our approach can lead to a deterministic SPS.
