Abstract

Here, we’ll review recent work suggesting that even low temperature annealing of optical fibres exposed to UV light leads to nanoscale changes in physical dimensions of waveguides. These changes are responsible for many observations made with gratings within trimaterial fibre systems and we will show that these changes can be significant with appropriate fibre composite design, particularly when a doped inner cladding is present. Long period gratings (LPGs) offer tremendous sensitivity to these changes which can explain some of the insensitivity to temperature observed even in conventional LPGs. These are compared with regenerated LPGs.

© 2015 Optical Society of America