Zero-Padding and Window Overlap Optimization for High-Spatial-Resolution OFDR

Optical frequency domain reflectometry (OFDR) generally employs a sliding-window analysis for distributed sensing, and the window parameters directly determine the spatial resolution and sensing performance of the system. In this work, the effects of zero-padding and window overlap on OFDR sensing performance were investigated. Experimental results demonstrate strain measurements from 0 μɛ to 2000 μɛ with a spatial resolution of 13.64 mm, achieving a sensitivity of 0.15 GHz/μɛ. The standard deviation of the measured strain in the nominally unstrained region was 1.20 με. Furthermore, temperature measurements from 25 °C to 75 °C achieved a sensitivity of 1.42 GHz/°C, and the standard deviation of the measured temperature in the unheated region was 0.15 °C. With the proposed method, sensing performance can be improved while maintaining the same spatial resolution. The proposed method provides a simple and hardware-independent approach for improving OFDR sensing performance.