Finite Element Analysis of Microbending Losses for Plain-weave GFRP Packaging Optical Fiber Sensor

Optical fibers are normally embedded or packaged into glass fiber-reinforce polymer (GFRP) structures due to their interesting properties for sensing. However, the embedding or packaging process induces lateral pressure to the optical fiber, which could easily lead to microdistortions in the cylindrical shape of the optical fiber, inducing microbending optical losses. In this paper, finite element simulations are used to analyze the influence of the pressure induced by GFRP packaging on microbending optical losses. Results also show that the degree of transmission microbending losses in the optical fiber may significantly vary under different displacement loads. Experimental results, based on a large depth-of-field photo, also confirm that large amount of light can escape the optical fiber as a result of the GFRP packaging process.