The optical multimode approach is suitable for practical applications because connection is relatively easy due to the large diameter of waveguide (around 50 μm). The problem is that massive parallelization is required in order to handle large capacity optical signals. We have the technology for fabricating 96 ch multimode polymer optical waveguides, mounting high-density (125 μm spacing) multicore (24 ch) optical connectors, and high-speed optical signal evaluation technology (Fig. 1).

Schematic structure

Prototype sample

Figure 1: Opto-electrical hybrid package board with integrated multimode polymer optical waveguides and multicore optical cable with optical connectors for circuit boards

Since wavelength multiplexing can be used with single-mode light, it is possible to handle high-speed signals in excess of 10 Tbps. However, since the waveguide diameter is only 10 μm, optical mounting is difficult. Furthermore, the optical waveguide of silicon photonics that has been attracting attention in recent years has become even smaller at less than 1 μm2, which cannot be handled by current technology. Because of this, we have been conducting research and development related to single-mode opto-electronic co-packaging which integrates each of the components from research and development to create technology for optical mountings for single-mode silicon photonic devices, and for optical packaging. More specifically, we fabricated a prototype three-dimensional mirror for silicon photonics (Fig. 2) and a prototype single-mode polymer waveguide (Fig. 3), mounted an optical connector on a single-mode polymer waveguide, and performed an evaluation of each.

Figure 2 Three-dimensional mirror for silicon photonics

Figure 3 Single-mode polymer waveguide and corresponding single-mode beam properties

• Optical packaging
• Polymer optical waveguide fabrication and evaluation
• Optical connector design and mounting
• High-speed optical signal evaluation