We have developed "tapered self-written waveguide (SWW)" for coupling of optical components in the board level optical interconnection. Tapered waveguides have a possibility of achieving larger alignment tolerance for optical coupling. The fabrication condition of tapered SWW was studied by adjusting both the optical power and irradiation time of curing resin, and tapered SWW was successfully realized. The optical tolerance vertical to the optical axis twice as compared with straight SWW was obtained.
In the optical interconnection of board level, 45-degree micro mirrors are used to achieve 90-degree optical path change. These mirrors are often fabricated by using a rotating blade and this method has a serious problem of cutting other waveguides in the vicinity. A self-written waveguide ha been successfully applied to repari and connect these waveguides. So, it will be possible to allow optical signals to be input and output at a specific location on the board.