2015/04/28 by Xueshi Guo, Nannan Liu, Guo, Xueshi +6
Computer Science · Engineering · #FOS: Physical sciences #Neural Networks and Reservoir Computing #Optical Network Technologies #Optics (physics.optics) #Quantum Information and Cryptography #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1504.07345
openalex publication_date 2015/04/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
One of the important function in optical communication system is the\ndistribution of information encoded in an optical beam. It is not a problem to\naccomplish this in a classical system since classical information can be copied\nat will. However, challenges arise in quantum system because extra quantum\nnoise is often added when the information content of a quantum state is\ndistributed to various users. Here, we experimentally demonstrate a quantum\ninformation tap by using a fiber optical parametric amplifier (FOPA) with\ncorrelated inputs, whose noise is reduced by the destructive quantum\ninterference through quantum entanglement between the signal and the idler\ninput fields. By measuring the noise figure of the FOPA and comparing with a\nregular FOPA, we observe an improvement of 0.7+-0.1 dB and 0.84+-0.09 dB from\nthe signal and idler outputs, respectively. When the low noise FOPA functions\nas an information splitter, the device has a total information transfer\ncoefficient of Ts+Ti=1.47+-0.2, which is greater than the classical limit of 1.\nMoreover, this fiber based device works at the 1550 nm telecom band, so it is\ncompatible with the current fiber-optical network.\n