A DESIGN CONSIDERATION FOR OPTICAL POWER DIVIDERS COMPOSED OF 3 COUPLED WAVE-GUIDES

In the present paper, we propose a design consideration for optical po wer dividers utilizing the distributed coupling among three adjacent s lab waveguides. This type of power divider can easily be fabricated by means of the process of ion-exchange. However, being large in scale i s a serious problem. We clarify that the size of the device can be rem arkably reduced by introducing nonuniformly distributed coupling which is caused by step-like gap variations between the waveguides. In orde r to obtain wide separations at the output end, we also introduce the low-loss bent structure which is designed by the method of suppression of the optical wave undulation along the waveguide. The numerical res ults show that low-loss wide separations of optical waves are possible and over a 35% reduction in device length can be achieved. The numeri cal analysis is based on the two-dimensional Finite Difference Method.