Mid infrared integrated quantum photonics is a promising platform for applications in sensing and metrology. However, there are only few examples of on-chip single photon sources at these wavelengths. These have limited performances with respect to their C-band counterparts. In this work, we demonstrate a new approach to generate heralded single photons in the mid infrared on a silicon chip. By using a standard C-band pump, the inter-modal spontaneous four wave mixing enables the generation of the herald idler at 1259.7 nm and the heralded signal at 2015 nm. The idler photon is easily detected with a common infrared single photon detector while the signal photon is upconverted to the visible before its detection. In this way, we are able to operate a mid infrared source without the need of mid infrared detectors and laser sources. By measuring a heralded g(2) of 0.23±0.08 we demonstrate the single photon behaviour of the source as well as the feasibility of multi-photon coincidence measurements beyond 2 μm with our setup. The source exhibits a high intrinsic heralding efficiency of (59±5)%, a maximum coincidence to accidental ratio of 40.4±0.9 and a generation probability of (0.72±0.10) W−2.
@article{arxiv.2108.01031,
title = {A silicon source of heralded single photons at 2 $\mu$m},
author = {S. Signorini and M. Sanna and S. Piccione and M. Ghulinyan and P. Tidemand-Lichtenberg and C. Pedersen and L. Pavesi},
journal= {arXiv preprint arXiv:2108.01031},
year = {2021}
}