Temperature dependence of macrobending loss in all-fiber bend loss edge filter

Abstract

A theoretical model for macrobending-induced temperature dependent loss (TDL) for a standard singlemode fiber (SMF28) with dual coating layers is presented, with good agreement demonstrated between theoretical calculations and experimental results. The impact of temperature on two examples of an all-fiber based edge filter is also investigated theoretically and experimentally and using the developed model, it is shown that it is possible to predict the impact of temperature variations on an all-fiber based edge filter.

Temperature dependence of a macrobending edge filter based on a high-bend loss fiber

“…However, in our previously published investigations [6,7], it was found that the fiber polymer coating layer, which provides mechanical protection for the fiber, has a significant influence on both fiber bending loss and polarization dependent loss. For the fiber bend loss edge filter application, such coating layer(s) can also induce random variations throughout the measured transmission spectrum [8].…”

“…In practice, in the experiments in [8] it was found that changes in temperature affected the measured bending loss. Upon investigation it was realized that because the bend loss of 1060XP is approximately two times more temperature sensitive than SMF28, so the spectral response of an edge filter based on 1060XP fiber would be more temperature dependent.…”

“…2, it is shown that the modeled TDL results (Plot A) demonstrate a strong monotonic increase from a start temperature (0 o C) to an end temperature (80 o C). For a SMF28 fiber base edge filter [8], it is found that the TDL display several strong periodical bending loss response at different bend radii due to whispering gallery modes (WGMs) effects guided at cladding-coating interface, whereas for bare 1060XP fiber presented in Fig. 2, it is clearly that the TDL changes monotonically over the measured temperature range from a start temperature (0 o C) to an end temperature (80 o C), such TDL performance is significantly different with that of coated SMF28, this indicates that temperature variations induced periodical bending loss response of coated fiber is mainly caused by coatings, and the striped bare fiber with absorbing layer has effectively reduced the impact of WGMs.…”

Analysis and performance evaluation of an all-fiber wide range interrogation system for a Bragg grating sensor array

“…Ambient temperature variation is another factor that can create inaccuracies in the measured wavelength of systems based on macro-bend fiber filters. Earlier investigations on macro-bend fiber edge filters show that the buffer coating layer has a significant effect on the temperature dependence of the filter [15,16,24]. Due to whispering gallery modes induced oscillatory variations in the bend loss and hence in the ratio, and the different ratio variations at different wavelengths, a correction in the calibration response required to compensate for temperature variation is very complex for systems based on SMF28 fiber filter.…”

“…Earlier investigations of the properties of a macro-bend fiber filter showed that a macro-bend fiber exhibits polarization dependent loss (PDL) [13,14] and temperature dependent loss (TDL) [15,16] and both these phenomena are functions of wavelength and also depend on the slope of the system which is determined by the bend radius and number of bend turns of the fiber filter. Furthermore the signal-to-noise ratio (SNR) of the source and the noise in the receiver limits the resolution of the system [17].…”