New method for making fiber optic Bragg gratings

Abstract

The use of a focused ion beam (FIB) to fabricate novel fiber optic structures is described. Using a FIB in either the ion milling mode or deposition mode a large variation in the index of refraction may be introduced in the optical fiber. With a potential beam size as small as 0.02 micrometers , the FIB process provides the ability to both expand the variety and reduce the size of structures that maybe embedded in optical fiber. For example, estimates indicate that a 20 groove Bragg grating coupled to 10 percent of the guided more energy can achieve a maximum 98 percent reflectivity. CUrrent drawbacks of the FIB process include slow production time and high production cost.