Single-mode fiber directional couplers fabricated by twist-etching techniques (stabilization)

Rugged single-mode fiber couplers have been fabricated by two different techniques: 1) twist-etch RTV potting, and 2) twist-etch gel glass potting. The performances, in terms of optical stability, mechanical ruggedness, and lifetime, are compared between the couplers made by these two techniques, and also with those of the original twist-etched (bottle) coupler reported earlier.