Scalable quantum optical tap for the distribution of quantum information encoded in entangled fields

We study two squeezed-state-dependent schemes of the quantum optical tap for information encoded in quantum-correlated fields from a two-mode entangled source. We find that, by using two independent squeezed beam splitters, the quantum information encoded in entangled dual beams can be divided into four parts without noise increase. We calculate the corresponding transfer coefficients to confirm that quantum optical tapping is achieved. As a variation to the original tapping schemes, we consider parametric amplifiers to replace beam splitters as tapping devices and find that they work equally well and have the advantage of tolerance to external losses. We also analyze the scalability of the schemes by cascading two outputs into the next stage and find that the output signals of the first stage can be further split noiselessly by the second stage. This shows that the scheme is cascadable and scalable for efficient quantum information distribution in an optical network.