Fabrication and characterisation of long, narrowband fibre gratings by phase mask scanning

Abstract

Fibre Bragg gratings up to 50 mm in length have been fabricated using a phase mask scanning technique. Reflectivities of up to 70% and linewidths as narrow as 0.029 nm have been measured. The fabrication technique lends itself to writing gratings with controllable length, chirp and shading.