Patent ID: 8103167

Claim:
A free space optical (FSO) communication system comprising a receiver node ( 1 ) and a transmitter node ( 2 ) communicating to each other via a control data communication channel and an information data communication channel operating at a wavelength region different from the wavelength region of the control data communication channel, said receiver node ( 1 ) including: (i) a receiver unit ( 11 ) configured to receive an information data signal provided by the transmitter node through the information data communication channel, and to recover information from said information data signal, wherein said receiver unit ( 11 ) is a high sensitivity angle-diversity optical data receiver that includes: a receiving assembly ( 110 ) configured for receiving the information data signal sent by the transmitter node ( 2 ); an array of detectors ( 113 ) arranged downstream of said receiving assembly; an information recovering unit ( 118 ) configured for providing the information data recovered from the information data signal; (ii) an interrogator unit ( 12 ) configured for generating and radiating an interrogation data signal through the control data communication channel in order to initiate and terminate an information data communication session between the receiver node ( 1 ) and the transmitter node ( 2 ); and (iii) a receiver node controller ( 13 ) coupled to the receiver unit ( 11 ) and to the interrogator unit ( 12 ) and configured to monitor characteristics of the control data communication channel and information data communication channel, and to control operation of the receiver unit ( 11 ) and the interrogator unit ( 12 ); said transmitter node ( 2 ) including: (iv) a responder unit ( 21 ) being responsive to said interrogation data signal radiated by the interrogator unit ( 12 ) and configured to locate the presence of the interrogator unit ( 12 ); (v) a transmitter unit ( 22 ) configured to receive the digitally encoded data from an information source, generate and radiate the information data signal through said information data communication channel to the receiver unit ( 11 ), wherein the transmitter unit ( 22 ) includes: a transmitter current driver ( 221 ) coupled to an information source, a transmitter multiplexer ( 222 ) arranged downstream of the current driver ( 221 ), a spatially multiplexed array of transmitters (SMART) ( 223 ) arranged downstream of the multiplexer ( 222 ); and an optical beam shaping element ( 224 ) arranged downstream of the SMART ( 223 ); and (vi) a notifier unit ( 23 ) coupled to the transmitter unit ( 21 ) and to the responder unit ( 22 ), and configured to control operation thereof.