We present a method of tomography that measures the joint spectral phase (JSP) of spontaneously emitted photon pairs originating from a largely uncharacterized ``target" source. We use quantum interference between our target source and a reference source to extract the JSP with four spectrally resolved measurements, in a process that we call quantum-referenced spontaneous emission tomography (Q-SpET). We have demonstrated this method on a photonic integrated circuit for a target micro-ring resonator photon-pair source. Our results show that spontaneously emitted photon pairs from a micro-ring resonator are distinctively different from that of stimulated emission, and thus cannot in general be fully characterized using classical stimulated emission tomography without detailed knowledge of the source.
@article{arxiv.2212.12521,
title = {Quantum-Referenced Spontaneous Emission Tomography},
author = {I. I. Faruque and B. M. Burridge and M. Banic and M. Borghi and J. E. Sipe and J. G. Rarity and J. Barreto},
journal= {arXiv preprint arXiv:2212.12521},
year = {2023}
}