Quantum Cloning with an Optical Fiber Amplifier
Sylvain Fasel, Nicolas Gisin, G. Ribordy, Valerio Scarani, Hugo Zbinden · Physical Review Letters · 2002
It has been shown theoretically that a light amplifier working on the physical principle of stimulated emission should achieve optimal quantum cloning of the polarization state of light. We demonstrate close-to-optimal universal quantum cloning of polarization in a standard fiber amplifier for telecom wavelengths. For cloning 1-->2 we find a fidelity of 0.82, the optimal value being 5 / 6=0.83.