Numerical modeling of intensity-based optical fiber Bragg grating sensor interrogation systems

We present a numerical model of intensity-based interrogation systems for optical fiber Bragg grating (FBG) sensors. The numerical model is based on previous analytical modeling, which could only be utilized for perfect Gaussian profiles. However, FBG interrogation systems can make use of non-Gaussian shaped filters or sources. The numerical modeling enables the different variations to be compared using identical component performance, showing the relative strengths and weakness of the systems in terms of useful parameters, including sensitivity and dynamic range. The two different detection methods for intensity-based FBG sensors can also be compared side by side using the same FBG. Since the model is numerical, it enables real spectral data to be used for the various components (FBG, light source, filters). This has the added advantage of increasing the accuracy and usefulness of the model over previous analytical work.