Long periodic superstructure Bragg gratings in opticalfibres

Abstract

A 40mm long optical fibre grating superstructure is written by translating an ultraviolet writing beam along a fibre and phase-mask assembly while its intensity is periodically varied. The grating reflects at multiple wavelengths, equally spaced by 0.13 nm, over a range of more than 1.0 nm. This grating structure has applications in signal processing and tunable fibre lasers.