Chirped gratings produced in photosensitive opticalfibres byfibre deformation during exposure

Abstract
A technique for writing chirped-period gratings by UV exposure in photosensitive optical fibres is reported. Results are presented for gratings produced in boron-germania codoped fibres, hydrogen-loaded high-germania fibres, and hydrogen-loaded standard telecommunications fibres, with performance parameters ranging from 99% reflectivity with 7.5 nm bandwidth, to ~5% reflectivity over >17nm bandwidth.