Yuji Wada

Abstract This paper presents the first investigation into how the dry etching depth of the reinforcement layer in perfluorinated polymer optical fibers (PF‐POFs) influences radial stress distribution. Using finite element method simulations, we model the PF‐POF structure based on the actual dry‐etched profiles achieved through reactive ion etching (RIE). The results demonstrate that increasing the etching depth leads to higher radial stress in both the core and cladding layers when strain is applied longitudinally. These findings suggest that RIE processes present a feasible method for tuning the sensitivity of PF‐POF‐based strain sensors. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.