Bragg gratings written in Sn-Er-Ge-codoped silica fiber: investigation of photosensitivity, thermal stability, and sensing potential.
Bragg gratings were fabricated in an Sn-Er-Ge-codoped silica fiber with a phase mask and ultraviolet radiation from a 248-nm KrF excimer laser. The photosensitivity of the fiber was examined by studying the initial growth rate of the gratings written into it. The thermal stability of the gratings was investigated and modeled in terms of both the refractive-index modulation and the effective refractive index of the fiber core. It was shown that the temperature-induced irreversible shift in the Bragg wavelength could not be predicted by the isothermal decay of the refractive-index modulation. Finally, the potential of the gratings written into the fiber is discussed in terms of their use in high-temperature-sensing applications.
School of Engineering and Mathematical Sciences, City University, London ECI V OHB, UK. S.Pal@city.ac.uk
Suchandan
S
Pal
Tong
T
Sun
Kenneth T V
KT
Grattan
Scott A
SA
Wade
Stephen F
SF
Collins
Gregory W
GW
Baxter
Bernard
B
Dussardier
Gérard
G
Monnom