A novel simple 3D SU8 prism-SOI waveguide interface for light coupling improvement

This paper presents optimized structural interface between 3D SU8 prism and SOI waveguide for reduced coupling loss at the interface, hence increasing light transmission efficiency over the system. The coupling loss reduced to 10 % at each optimized interface thanks to SU8 overlap on tip of SOI waveguide and partly etched BOX under the interface. With large tolerance up to 5 μm, the interface can be easily fabricated.