Abstract

The beam propagation method¹ is used to stimulate the propagation of light through Y junctions. Such structures have been extensively studied in the past, but the effect of junction rounding on the propagation characteristics has not been considered before. For photolithographically patterned, dry etched Y junctions, junction rounding usually leads to the branching point of the junction being 1–20 μm away from the position where it would have been if it were sharp. This work describes the effect of junction rounding on the propagation characteristics of symmetric and asymmetric Y junctions. The total power in each arm and the power in the fundamental mode is plotted as a function of propagation distance for different junction angles, input field distributions, and extents of junction rounding. We find that junction rounding has a surprisingly small effect on the propagation characteristics, so that it will have almost no detrimental impact on the experiments.

© 1991 Optical Society of America