| 摘要 |
An optical wireless communications system ( 1 ) comprises a server or transceiver hub ( 6 ) transmitting and/or receiving optical communications with geographically dispersed subscriber units ( 8 ) via optical beams. The transceiver hub ( 6 ) transmits a beam pattern that has an efficient, rectangular, flat-topped far field optical profile, thus permitting less complex and less expensive transceiver equipment to be employed in the transceiver hub ( 6 ) and in the subscriber units ( 8 ). In one embodiment, the transceiver hub ( 6 ) comprises an optical source ( 52 , FIG. 3 ), an asymmetrical lens such as a cylindrical lens ( 60 , FIG. 3 ), and a diffraction element such as a diffractive phase plate ( 65 , FIG. 3 ). Various methods of shaping an optical transmission profile are also described.
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