A scheme based on single photon detectors for laser communication

We introduce a new scheme based on single photon detectors for laser communication, where the sending terminal uses four polarization states of photons to code information via the transmission of quantum channel, and the receiving terminal decodes the information according to the responses of the four polarization-related single photon detectors. Simulation results show that the system's dark counts have little impact on the channel capacity, while the average photon numbers are the key factor to the systems performance. The channel capacity can be up to a maximum of l.77 bit per symbol. Using the polarization-dependent single photon detection technology for laser communication can effectively improve the systems energy utilization and reduce the effect of noise on the communication. (authors)