Abstract

Directional couplers fabricated by the fuse-pull-and-taper technique can be made from either two identical fibers or two dissimilar (in diameter and refractive-index profile) fibers.¹ The latter device is termed a tuned-port coupler and has interesting wavelength-selective properties.² We present evidence that the power-transfer mechanism in the dissimilar fiber splitter reported in Ref. 1 is due to a new coupling mechanism. We also report the automated manufacture and characterization of fused directional couplers and the application of the characteristic curve of power transfer vs coupler length (i.e., its pull signature) to the optimization of the fabrication process.

© 1987 Optical Society of America