Architecture of an all optical de-multiplexer for spatially multiplexed channels

Multiple channels of light can propagate through a multimode fiber without interfering with each other and can be independently detected at the output end of the fiber using spatial domain multiplexing (SDM). Each channel forms a separate concentric ring at the output. The typical single pin-diode structure cannot simultaneously detect and de-multiplex the multiple channel propagation supported by the SDM architecture. An array of concentric circular pin-diodes can be used to simultaneously detect and de-multiplex the SDM signals; however, an all optical solution is generally preferable. This paper presents simple architecture for an all optical SDM de-multiplexer.