Abstract

The distribution of optical signals from one to several points in optical communication networks is necessary. However, problems exist in fabri- eating all fiber single-mode star couplers. In this paper, an integrated-optical version of 1 × N star couplers is presented. It offers the advantages of reproducibility, ease of fabrication, distribution uniformity, and polarization preservation. The principle of operation is based on directional cou- pllng among sets of tapered velocity couplers.¹ This method enhances the design objective of minimizing the losses, which are commonly encountered at corner bends or Y-junctions, while allowing for accurate and efficient coupling to single-mode fiber arrays with maximum output power distribution uniformity. The basic geometry is shown in Fig. 1 for three slightly different structures. The three configurations are based on the same concept of distributed coupling between sets of single-mode channels whose spacing is linearly Increased within and beyond the coupling regions. The design allows for uniform spacing of the parallel output channels normal to the edge at which the single-mode fiber array is connected.

© 1983 Optical Society of America