Photoreceiver arrays with near-quantum limit performance for free space optical communications

Photoreceiver array configurations for enhancing the sensitivities of free space optical terminals down to the quantum limits are described. Small format arrays at 1550-nm have been implemented and shown to improve sensitivity by 1.8 dB. The concept of large format arrays based on optically preamplified photoreceivers in a summed configuration for is elucidated and shown to be capable of sensitivities as low as -53 dBm at 2.5 Gbps bit rate and 10 -9 BER for (8 times 8) arrays