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arXiv · 1707.08787

Coherent frequency bridge between visible and telecommunications band of vortex light

Shi-long Liu·Shi-kai Liu·Yin-hai Li·Shuai shi·Zhi-yuan Zhou·Bao-sen Shi
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Abstract

In quantum communications, vortex photons can encode higher-dimensional quantum states and build high-dimensional communication networks (HDCNs). The interfaces that connect different wavelengths are significant in HDCNs. We construct a coherent orbital angular momentum (OAM) frequency bridge via difference frequency conversion in a nonlinear bulk crystal for HDCNs. Using a single resonant cavity, maximum quantum conversion efficiencies from visible to infrared are 36\%, 15\%, and 7.8\% for topological charges of 0,1, and 2, respectively. The average fidelity obtained using quantum state tomography for the down-converted infrared OAM-state of topological charge 1 is 96.51\%. We also prove that the OAM is conserved in this process by measuring visible and infrared interference patterns. This coherent OAM frequency-down conversion bridge represents a basis for an interface between two high-dimensional quantum systems operating with different spectra.

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Shi-long Liu, Shi-kai Liu, Yin-hai Li, Shuai shi, Zhi-yuan Zhou, Bao-sen Shi. 2017-09-26. Coherent frequency bridge between visible and telecommunications band of vortex light. https://doi.org/10.1364/oe.25.024290

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