Fiber Bragg grating (FBG) sensors have proven to be adaptable for monitoring various physical quantitites
like temperature, strain, or even vibrations and acoustic noise. Several interrogation methods, like spectroscopic
evaluation, interferometric interrogation, active scanning or active filtering systems or passive filtering systems are
capable of monitoring the wavelengths of the FBG sensors. Among the passive filtering systems, interrogators
based on arrayed waveguide gratings (AWG) have shown to be promising candidates for sensing with FBGs,
especially for high-frequency measurement tasks.
Whereas the resolution- and the accuracy-dependency on light intensity of direct wavelength determining systems
like spectrometers or scanning filter systems can be minimized by data processing algorithms, the performance
of passive filtering based interrogators is more sensitive regarding uncertainties induced by electrical amplifier
noise, FBG peak shape, light source intensity, etc.. The influence of different sources of uncertainties for AWGbased
interrogators on the accuracy of the wavelength determination are investigated by an analytical model.
The model is evaluated by a numerical simulation. It is shown how strongly the accuracy and the resolution of
such an interrogator depend on the mentioned sources of uncertainties. Considering the obtained results, one
can say that FBG interrogators based on arrayed waveguide gratings have, including the shown restrictions, the
potential for rugged, compact and cost effective high accuracy wavelength interrogators.