160 Gb/s Bidirectional Polymer-Waveguide Board-Level Optical Interconnects Using CMOS-Based Transceivers

We have developed parallel optical interconnect technologies designed to support terabit/s-class chip-to-chip data transfer through polymer waveguides integrated in printed circuit boards (PCBs). The board-level links represent a highly integrated packaging approach based on a novel parallel optical module, or Optomodule, with 16 transmitter and 16 receiver channels. Optomodules with 16 Tx+16 Rx channels have been assembled and fully characterized, with transmitters operating at data rates up to 20 Gb/s for a 2⁷-1 PRBS pattern. Receivers characterized as fiber-coupled 16-channel transmitter-to-receiver links operated error-free up to 15 Gb/s, providing a 240 Gb/s aggregate bidirectional data rate. The low-profile Optomodule is directly surface mounted to a circuit board using convention ball grid array (BGA) solder process. Optical coupling to a dense array of polymer waveguides fabricated on the PCB is facilitated by turning mirrors and lens arrays integrated into the optical PCB. A complete optical link between two Optomodules interconnected through 32 polymer waveguides has been demonstrated with each unidirectional link operating at 10 Gb/s achieving a 160 Gb/s bidirectional data rate. The full module-to-module link provides the fastest, widest, and most integrated multimode optical bus demonstrated to date.