Optical quantum memory is a device that can store the quantum state of photons and
retrieve it on demand and with high fidelity. It is emerging as an essential device to
enhance security, speed, scalability, and performance of many quantum systems used in
communications, computing, metrology, and more. In this paper, we will specifically
consider the impact of optical quantum memory on quantum communications systems.
Following a general overview of the theoretical and experimental research progress in
optical quantum memory, we will outline its role in quantum communications, including as
a photon source, photon interference, quantum key distribution (QKD), quantum
teleportation, quantum repeater, and quantum networks.
Preliminary design of the beam loss monitor system for the advanced photon source
