An optical add-drop multiplexer with a grating-loaded directional coupler in silica waveguides is demonstrated. The device for this configuration has a large fabrication tolerance and is small in size. A new scheme, in which the coupling length of the directional coupler is twice the complete coupling length, enables low cross-talk for both add and drop operations. This device is polarization-independent due to its relatively low-temperature process.

An optical add-drop multiplexer with a grating-loaded directional coupler in silica waveguides is demonstrated. The device for this configuration has a large fabrication tolerance and is small in size. A new scheme, in which the coupling length of the directional coupler is twice the complete coupling length, enables low cross-talk for both add and drop operations. This device is polarization-independent due to its relatively low-temperature process.

Silicon photonic devices based on silicon photonic wire waveguides are especially attractive devices, since they can be ultra-compact and low-power consumption. In this paper, we demonstrated various devices fabricated on silicon photonic wire waveguides. They included optical directional couplers, reconfigurable optical add/drop multiplexers, 12, 14, 18 and 44 optical switches, ring resonators. The characteristics of these devices show that silicon photonic wire waveguides offer promising platforms in constructing compact and power-saving photonic devices and systems.

One of the most serious challenges facing the exponential performance growth in the information industry is a bandwidth bottleneck in inter-chip interconnects. We therefore propose a photonics-electronics convergence system with a silicon optical interposer. We examined integration between photonics and electronics and integration between light sources and silicon substrates, and we fabricated a conceptual model of the proposed system based on the results of those examinations. We also investigated the configurations and characteristics of optical components for the silicon optical interposer: silicon optical waveguides, silicon optical splitters, silicon optical modulators, germanium photodetectors, arrayed laser diodes, and spot-size converters. We then demonstrated the feasibility of the system by fabricating a high-density optical interposer by using silicon photonics integrated with these optical components on a single silicon substrate. As a result, we achieved error-free data transmission at 12.5 Gbps and a high bandwidth density of 6.6 Tbps/cm2 with the optical interposer. We think that this technology will solve the bandwidth bottleneck problem.