HYBRID FREE-SPACE OPTICAL BUS SYSTEM FOR BOARD-TO-BOARD INTERCONNECTIONS

A free-space optical bus system is described for board-to-board interc onnections at the backplane level. The system uses active optoelectron ic modules as the interface between the circuit boards and the electri cal backplane. Substrate-mode holograms are used to implement signal b roadcast operations between boards, and each board on the backplane sh ares common free-space channels for transmitting and receiving signals , System-design considerations are given, and the potential performanc e of the optical bus system is evaluated. An experimental demonstratio n is also presented for the signal broadcast operation through cascade d substrate-mode holograms at a data rate of 622 Mb/s. (C) 1996 Optica l Society of America