Rapidly increasing broadband access has led to the requirement for much higher transmission throughput within a network equipment. The most promising solution is optical interconnection using an optical backplane. We have developed a high-density optical backplane using a small-diameter optical fiber to realize multi-tera bit/s throughput. To achieve this, we developed a new high-delta and small-diameter optical fiber (clad diameter=80μm, coating diameter=125μm), a high-den-sity optical fiberboard with small bending radius (r=5mm), a high-density MT ferrule, an easy assemble MT ferrule and compact optical right angle connector. Using these new devices, we fabricated a high-density optical backplane, which complies with the structure of an ATCA backplane. It has achieved a high throughput performance of 3 Tbit/s, which is five times that of an electric backplane.