Mj. Cole et al., MOVING FIBRE PHASE MASK-SCANNING BEAM TECHNIQUE FOR ENHANCED FLEXIBILITY IN PRODUCING FIBER GRATINGS WITH UNIFORM PHASE MASK/, Electronics Letters, 31(17), 1995, pp. 1488-1490
A new and flexible technique for producing photorefractive fibre grati
ngs with a uniform phase mask is demonstrated. By slowly moving the fi
bre relative to the mask as the writing beam is scanned, wavelength sh
ifts, pure apodisation and phase-shifted gratings can be achieved.