Detection of aliasing in sampled dynamic fiber Bragg grating signals recorded by spectrometers

Spectrometers based on linear detector arrays have proven to be capable of precisely monitoring fiber Bragg grating (FBG) signals. However, anti-aliasing inherently is only poorly integrated. Thus, these devices do not suffice for providing a reliable anti-aliasing in critical applications like real-time structure control. We present a method that allows the detection of aliased signals in sampled FBG spectra time series of FBG sensors under sinusoidal loads. The method is proven by numeric system simulations and an experimental verification for sinusoidal loads on a fiber Bragg grating. The procedure allows to extend the use of spectrometer-based interrogators, for example in dynamic control loops, by providing a measure for the reliability of sampled dynamic FBG signals.