title: High-sensitivity DPSK receiver for high-bandwidth free-space optical communication links.
abstract: A high-sensitivity modem and high-dynamic range optical automatic gain controller (OAGC) have been developed to provide maximum link margin and to overcome the dynamic nature of free-space optical links. A sensitivity of -48.9 dBm (10 photons per bit) at 10 Gbps was achieved employing a return-to-zero differential phase shift keying based modem and a commercial Reed-Solomon forward error correction system. Low-noise optical gain was provided by an OAGC with a noise figure of 4.1 dB (including system required input loses) and a dynamic range of greater than 60 dB.
authors.affiliation: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, USA. Juan.Juarez@jhuapl.edu
authors.forename: Juan C
authors.initials: JC
authors.lastname: Juarez
authors.forename: David W
authors.initials: DW
authors.lastname: Young
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Sluz
authors.forename: Larry B
authors.initials: LB
authors.lastname: Stotts