Spatial and spectral characterization of photon pairs at telecommunication-wavelength from type-0 spontaneous parametric down-conversion

Abstract: The thorough characterization of entangled-photon sources is vital for their optimal use in quantum communication. However, this task is not trivial at telecommunication wavelengths. While cameras and spectrometers are well developed for visible and near-infrared spectra, that does not apply in the mid-infrared range. Here we present a spatial and spectral characterization of photon pairs emitted in a type-0 phase-matched spontaneous parametric down-converted source. We experimentally show how these photon properties are modified by the crystal temperature. This parameter allows easy modification of photon-pair properties to fit novel multiplexing schemes based on only one entanglement photon source. Our results pave the way for the optimal design and use of spatial and spectral properties of quantum-correlated photon pairs at telecommunication wavelengths.