We have experimentally realized a technique to generate, control and measure entangled qutrits, 3-dimensional quantum systems. This scheme uses spontaneous parametric down converted photons and unbalanced 3-arm fiber optic interferometers in a scheme analogous to the Franson interferometric arrangement for qubits. The results reveal a source capable of generating maximally entangled states with a net state fidelity, F = 0.985 ± 0.018. Further the control over the system reveals a high, net, 2-photon interference fringe visibility, V = 0.919 ± 0.026. This has all been done at telecom wavelengths thus facilitating the advancement towards long distance higher dimensional quantum communication.
@article{arxiv.quant-ph/0307122,
title = {Experimental realization of entangled qutrits for quantum communication},
author = {R. T. Thew and A. Acin and H. Zbinden and N. Gisin},
journal= {arXiv preprint arXiv:quant-ph/0307122},
year = {2007}
}