Amplification of fibre Bragg grating reflectivity by post-writing exposure with a 193 nm ArF laser

Abstract
The reflectivity of weak in-fibre gratings (a few percent reflectivity) written by an ArF laser illuminated phase mask can be dramatically enhanced (reaching ≥ 95%) by subsequent exposure using a uniform ArF laser beam. This new effect offers the possibility of post-writing control of grating properties.