Fabrication of fiber optic Bragg gratings: effect of ultraviolet light absorption by the fiber buffer

Fiber-optic Bragg gratings are fabricated in hydrogen-loaded communications-grade optical fibers using 244 nm continuous wave light. The fiber-buffer is only partially stripped to allow the ultraviolet grating writing beam to enter the fiber. This light is completely absorbed by the buffer behind the fiber. The absorption of ultraviolet light by the buffer significantly increases the rate of formation of Bragg gratings. This is explained as being due to the heating effect on fiber due to the absorption of ultraviolet light.