Evaluating and Minimizing Induced Microbending Losses in Optical Fiber Sensors Embedded Into Glass-Fiber Composites

Abstract

Conventional silica optical fibers can be embedded into composite structures or packaging to provide structural monitoring capabilities. In this paper, the microbending optical losses induced by the packaging of a sensing optical fiber into a sandwiched glass-fiber reinforced structure are investigated experimentally and by simulations. Results show that the positioning of the optical fiber within a plain-weave glass fiberreinforced structure has a critical effect on microbending optical losses due to potentially induced microdeformations of the optical fiber's cylindrical shape. Similar analysis is also carried out with the use of a 1D glass-fiber layer packaging, demonstrating lower residual microbending losses after manufacturing. By the proper positioning of an optical fiber containing a series of wavelengthmultiplexed fiber Bragg grating (FBG) sensors over a 2D plainweave glass fabric, a 10-fold improvement in the induced optical losses is demonstrated, increasing the optical power that reaches the interrogating unit and allowing the monitoring of hundreds of meters over glass-fiber structures. Although all the analysis is focused and verified using a series of FBG sensors, the results and conclusions related to the induced microbending losses are also valid and useful for distributed optical fiber sensing approaches.

Analisa Bending Loss pada Fiber Optic Single-Mode

“…Fiber single-mode digunakan di pusat data untuk aplikasi jarak pendek dan jarak jauh karena transmisi mode tunggal yang mampu menghasilkan bandwidth sistem yang tinggi dan jangkauan yang lebih jauh, pusat data berskala besar serta cenderung mengadopsi serat optik mode tunggal standar sebagai media transmisi tunggal (Chen et al, 2019). Kerugian akibat pembengkokan pada serat optik telah diselidiki secara ekstensif selama hampir 40 tahun, terutama terkait dengan pembengkokan mikro dan makro (P. Zhu et al, 2021). Beberapa peneliti telah menemukan bukti empiris (C. Schulze et al, 2013) mengenai pengaruh faktor eksternal seperti tekanan yang dapat menyebabkan kelenturan pada serat optik.…”

Analysis of fiber loss in large angle laser parameter measurement

“…The former is often caused by the stresses due to difference in the thermal expansion coefficient between the fiber and the outer protective layer. Some high-order modes in the core are converted into radiation modes and leak into the cladding or even out of the fiber [12] . With the optimization of materials and the improvement of the manufacturing process, the micro-bend loss can be maintained below 2 dB/km.…”

Distributed Optical Fiber Strain Sensors Packaged with Polyurethane and GFRP

“…The packaging of bare fiber sensors can play the role of sensitization and protection [1] , and the packaged fiber sensor has stronger mechanical strength and longer service life. The bare-optical fiber sensors can be mainly packaged with glass fiber reinforced polymers (GFRP) prepreg via thermosetting heat curing [2][3] , and the packaging structure is a sandwich packaging structure. Firstly, two pieces of glass fiber prepreg are cut into the same size, and one of them is taken as the lower layering.…”