Abstract

Because of their potential applications in fiber communication systems, there is a considerable interest and possible profit in exploring new techniques for fabricating fiber Bragg gratings. For example, the photosensitivity of Ge-doped fiber to mid-UV (240 nm) light can be substantially improved by loading the fiber with molecular hydrogen before writing [1-3]. However, the strong absorption of 240 nm light in the fiber’s core causes the induced index change across the core to be non-uniform [4]. Also, strong absorption of 240 nm light can heat the core and cause a thermal reaction with molecular hydrogen [3] that saturates the index change and substantially reduces the contrast of the final grating.

© 1997 Optical Society of America