Spatial and spectral characterization of photon pairs at telecommunication wavelengths from type-0 spontaneous parametric downconversion

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, this 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 downconverted 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 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.