Mode multiplexing and holographic demultiplexing communication channels on a multimode fiber

Spatial mode multiplexing is used to transmit several communication channels on a single multimode optical fiber. Each channel is encoded by an orthogonal pattern produced by a spatial light modulator. A photorefractive medium holographically decodes the output speckle pattern at a receiver station. We demonstrate ring and star architectures for interconnection networks. Typical cross-talk-to-signal ratios, for fully interconnected three-processor networks, are -24 and -26 dB for the ring and star, respectively.