Investigation of Gaussian Apodized FBG Properties for the Analysis of Building Materials

Fiber Bragg Grating (FBG) sensors are very much applicable for measuring various parameters like temperature, strain, pressure etc. among other optical sensor due to its various advantage particularly in harsh environment. FBG can also be used for monitoring of various civil structures by measuring the sensitivity of physical parameters for different building materials. In this work the reflectivity and peak power value of several building materials with respect to the grating length has been discussed by using a gaussian apodized FBG. Effect of bandwidth has also been discussed with the change of grating length. The entire research work has been carried out in Opti-grating software for designing the apodized FBG. In some applications related to sensing, sidelobe suppression is much more important along with high reflectivity and narrow bandwidth. We have considered a Gaussian apodized FBG which removes all the side lobes of the reflection spectrum. Grating length can be represented as the most important parameter to improve the reflectivity and peak power of the spectrum. It has been observed that reflectivity increases from 31.28% to 97.46% and peak power value also increases from −5.0541 dB to −0.1115 dB if we increase the grating length of the FBG from 10 mm to 40 mm. Bandwidth is found to be decreased from 0.65 nm to 0.12268 nm with increasing grating length value from 10 mm to 40 mm for all the building materials.