Excimer laser writing of submicrometre period fibre Bragg gratings using phase-shifting mask projection

Submicrometre period, first-order Bragg gratings have been written in optical fibre, for the first time to the authors knowledge, by projecting a phase-shifting mask. Gratings with a peak reflectivity of 85% at a Bragg wavelength of 1530 nm were recorded using single pulses from a broadband KrF excimer laser