Development of Optical Pin Formation Process for Low-Profile Optical Modules

An optical pin is a vertical polymer optical waveguide on a silicon photonics substrate and is used for coupling with multimode optical fiber (MMF). In this study, we investigated the optimum shape of the optical pin for coupling with a polymer optical waveguide embedded in a printed circuit board. The optimum diameter obtained by ray-tracing simulation was 20 µm, which was smaller than that for coupling with an MMF. In addition, the optical pin formation process was developed by optimizing the exposure irradiance and exposure time.