On Entanglement Assisted Classical Optical Communication with Transmitter Side Optical Phase-Conjugation

Entanglement assisted (EA) communication has been advocated by numerous authors as a potential alternative to classical communications, in particular in noisy and low-brightness regime. In this paper, I propose an EA scheme employing the optical phase-conjugation (OPC) on transmitter side. I show that the proposed EA communication system, with the transmitter side OPC, significantly outperforms its classical counterpart in low-brightness and highly noisy regime, while employing a classical coherent detection scheme for two-dimensional demodulation. Moreover, the capacity of the proposed EA scheme is significantly higher than EA repetition-BPSK, homodyne, heterodyne, and Holevo capacities. Finally, the proposed EA scheme outperforms the corresponding EA scheme with OPC placed on a receiver side.