Three-Dimensional-Printed Fabrication of POFs Using Different Filaments and Their Characterization for Sensing Applications.

This paper presents the development and sensor applications of 3D-printed polymer optical fibers (POFs) using commercially available filaments. The well-known intensity variation sensor was developed using this fiber for temperature and curvature sensing, where the results indicate a linear response in the curvature analysis, with a coefficient of determination (R2) of 0.97 and sensitivity of 4.407 × 10-4 mW/∘, whereas the temperature response was fitted to an R2 of 0.956 with a sensitivity of 5.718 × 10-3 mW/∘C. Then, the POF was used in the development of a modal interferometer by splicing the POF in-between two single-mode fibers (SMFs), which result in a single-mode-multimode-single-mode (SMS) configuration. The such interferometer was tested for temperature and axial strain responses, where the temperature response presented a linear trend R2 of around 0.98 with a sensitivity of -78.8 pm/∘C. The negative value of the sensitivity is related to the negative thermo-optic coefficient commonly obtained in POFs. Furthermore, the strain response of the SMS interferometer showed a high sensitivity (9.5 pm/μϵ) with a quadratic behavior in which the R2 of around 0.99 was obtained. Therefore, the proposed approach is a low-cost, environmentally friendly and straightforward method for the production of highly sensitive optical fiber sensors.