Tadashi Enomoto

Long-period fiber grating in a pure-silica-core fiber written by residual stress relaxation

Summary form only given. Long-period fiber gratings (LPFGs) have recently been attracting much attention for their possible applications such as gain-flattening filters for erbium-doped fiber amplifiers. Most LPFGs have been written in germanosilicate optical fibers because periodic structures can be easily obtained using UV-induced refractive-index changes due to the photosensitivity of Ge-related glass defects. This technique requires that fibers for LPFGs should contain photosensitive sites, and thus it cannot be applied to those which have no photoreaction centers inside such as pure-silica core optical fibers. Here we report the efficient fabrication of LPFGs in pure-silica-core optical fibers by residual stress relaxation. We also present the thermal dependence of the loss peak of the LPFG.

Adequate aging condition for fiber Bragg grating based on simple power law model

Summary form only given. In summary, we have examined thermal decay of fibre Bragg gratings (FBG) for wide temperature and time range. Decay fitted well to a simple power law, and temperature dependence of decay suggests that the accelerated aging condition can be used to test for long-term reliability. This analysis is simpler than previous models and useful for decay estimation.