Compact multiplexing INTEGRATED PHOTONICS

Spatial multiplexers (SMUXs) for mode division multiplexing often involve multiple strategies for mode-selective excitation and the minimization of insertion and other losses. Haoshuo Chen, Roy van Uden, Chigo Okonkwo and Ton Koonen, working at the COBRA Institute at the Eindhoven University of Technology in The Netherlands, have reported a SMUX for mode division multiplexing that packages multiple strategies into compact components with a small footprint (Opt. Express 22, 31582–31594; 2014). They demonstrated photonic integrated SMUXs on both silicon-on-insulator (SOI) and indium phosphide (InP) platforms for selectively exciting modes.