Bloch Wave 방법을 이용한 광 픽업용 Focusing Waveguide Grating Coupler의 특성 분석

초록

The Focusing waveguide grating coupler (FWGC) is the device that focuses the beam diffracted from the waveguide and is very important for miniaturizing an optical pick-up head. In order to design the optimal FWGC for an optical pick-up head, the schematic structure of FWGC was determined from the fringe pattern, which was formed by the interference of a diverging guided-mode with a focusing beam. It coupling characteristic was analyzed using a Bloch wave approach. In particular, the dependency of the coupling coefficient on the period and thickness of grating was analyzed. Our results would be very useful for optimizing the detail grating structure of FWGC.