水素雰囲気下における光ファイバーブラッグ格子の水素負荷および熱処理に対する応答特性
This experimental study examined how the contrast and resonance wavelengths of fiber Bragg gratings evolve when subjected to molecular hydrogen loading at 8 MPa followed by heat treatment within a hydrogen atmosphere. Transmission spectra were recorded in situ during room-temperature hydrogen exposure and subsequent isochronal annealing up to 700°C at constant hydrogen pressure. The thermal decay dynamics differed markedly between hydrogen ambience and air, with the behavior depending on both the grating type and the glass composition of the fiber core. Based on these findings, the formation mechanism of type IIa gratings was revisited and discussed.
Molecular hydrogen interacts with the glass matrix of the fiber core, altering grating contrast and resonance wavelength. Thermal decay dynamics differ depending on whether annealing occurs in hydrogen or air, and vary with grating type and core glass composition.
The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/16926864