Temperature and strain characterization of regenerated gratings

Both temperature and strain characterization of seed and regenerated gratings with and without post-annealing is reported. The high temperature regeneration has significant impact to thermal characterization and mechanical strength of gratings whilst the post annealing has little effect. The observed difference is evidence of viscoelastic changes in glass structure.
Comment: Submitted to Optics Letters 10/10/2012; referees accepted; one who thought it should be submitted to JOSA. Currently being resubmitted elsewhere