We demonstrate a novel scheme for femto-second pulsed spontaneous parametric down-conversion in periodically poled KTP crystals. Our scheme is based on a crossed crystal configuration with collinear quasi-phase-matching. The non-degenerate photon pairs are split in a fiber-based wavelength division multiplexer. The source is easier to align than common pulsed sources based on bulk BBO crystals and exhibits high-quality polarization entanglement as well as non-classical interference capabilities. Hence, we expect this source to be a well-suited candidate for multi-photon state generation e.g. for linear optical quantum computation and quantum communication networks.
@article{arxiv.1404.6914,
title = {Crossed crystal scheme for fs-pulsed entangled photon generation in ppKTP},
author = {Thomas Scheidl and Felix Tiefenbacher and Robert Prevedel and Fabian Steinlechner and Rupert Ursin and Anton Zeilinger},
journal= {arXiv preprint arXiv:1404.6914},
year = {2014}
}