Electric-arc-induced gratings in non-hydrogenated fibres: fabrication and high-temperature characterizations

Temperature-insensitive long period grating sensors in photonic crystal fibre

“…This may be compared with the results of G. Humbert et al [4] who quote a temperature sensitivity of 9 pm/ºC in the range of 25-160 ºC for a similarly structured PCF, which however had different core and hole dimensions. By way of further comparison, the temperature sensitivity of electric arc-induced LPGs in standard single mode fibre is around 70 pm/ºC [5].…”

Temperature insensitive strain sensor based on long period fiber grating pair in photonic crystal fibers

“…The attenuation band slightly shifted to the longer wavelength in a monotonic and linear manner. The coefficients of spectral shift were measured to be ~ 4.6 pm/ C. This is significantly lower in comparison to conventional photorefractive SMF-LPGs which have a typical temperature dependency of 46 ~ 154 pm/ C in the temperature range of 25 to 250 C [6,7]. It is also noted that the full width half maximum (FWHM) of the resonant bands did not vary within experimental measurement error, which also confirm excellent temperature stability of the device.…”

Nondestructive index profiling of long period gratings in photonic crystal fibres

“…It has been reported in (Humbert and Malki 2002;) that the index change caused by arc is of the order of 10 −4 which is sufficiently small. Another study of the LPGs fabricated in PCFs by the same method shows that the holes collapse only after extremely long exposure to the arc (Morishita and Miyake 2004).…”