48×10 Gbps Cost-Effective FPC-Based On-Board Optical Transmitter with PGA Connector

High bandwidth density on-board optical transmitter is reported in this paper. This on-board transmitter contains 4×12-channel 10Gbps CMOS driver ICs and 4×12-channel 850nm Multimode (MM) VCSEL arrays, with a total 48×10Gbps bandwidth and is packaged through flip-chip bonding on a flexible printed circuit (FPC) with SnAg solder bumps. Due to the compact package design, based on a commercial 1mm pitch ISI HoLi pin grid array (PGA) connector, the size of FPC is only 31.5mm × 31.5mm and it offers a state-of-art bandwidth density of 0.483Gbps/mm2. Investigation of RF signal propagation on the FPC is carried out for design validation at 10Gbps and to further explore the potential of the suggested platform differential pairs are simulated up to 30Gbps. An optical straight lens connector is used to couple the light to a single 48 fibers MT connector. To validate the design concept the fully assembled transmitter is tested at 10Gbps. Bit error rates for all 48 channels at 10Gbps as well as eye diagrams for few representative channels are reported.