Enhanced Evanescent Field via Integration of Graphene Oxide/PMMA Hybrid Film on Coreless D-shaped Fibers

We present the first-ever demonstration of an evanescent field-based sensing structure utilizing a graphene oxide (GO)/poly(methyl methacrylate) (PMMA) hybrid film integrated on coreless D-shaped fibers (cDsFs). Theoretical and experimental analyses were conducted to elucidate the internal working mechanism of the hybrid film-coated cDsF (GoP-cDsF). Additionally, the performance of the cDsF with the PMMA film alone was employed as a reference for comparison. Our findings underscore the significant role played by the GO in enhancing the evanescent field, leading to a synergistic effect that contributes to the overall enhancement of the device's evanescent field. Consequently, the as-fabricated GoP-cDsF sensor demonstrates a remarkable sensitivity of -4.936 nm/°C, making it highly suitable for high-sensitivity temperature sensing applications. Furthermore, these attributes position the GoP-cDsF as a promising candidate for measuring both magnetic and electric fields, thereby offering a viable strategy for multifunctional sensing applications.