Local area network optical fiber data communication

A method and apparatus are disclosed for high speed multiaccess data communication using guided wave components and angular division multiplexing for parallel optical signal transmission over a multimode optical fiber. A receiver at each station in the network comprises an optical coupler/demultiplexer, a pulse regenerator, an optical processor and detectors. The transmitter at each station comprises an array of lasers, a switching matrix for controlling emissions into the optical fiber and a multiplexer/coupler for coupling the laser emissions to the multimode optical fiber. The optical processor is directly coupled to the switching matrix. Preferably, the multiplexer/coupler comprises a graded-index planar lens, one major surface of which abuts the optical fiber and the other major surface of which is contacted by a plurality of single mode waveguides from the different lasers of the transmitter. As a result, the single mode signals introduced into the lens at different radial distances are coupled to different modal groups propagating in the optical fiber. The coupler/demultiplexer preferably comprises a graded-index lens and an array of concentric half-ring lasers. Annular cones of radiation propagating in the optical fiber are focused to an array of concentric rings near the half-ring lasers where they are converted into linear beams propagating in single mode guided wave structures.