Self-integrated auxiliary interferometer for nonlinearity compensation in optical frequency domain reflectometry

An improved self-integrated auxiliary interferometer is proposed for efficient nonlinearity compensation in optical frequency domain reflectometry (OFDR). Unlike conventional methods that require separate auxiliary interferometers and additional detection channels, the proposed system integrates auxiliary functionality directly into the OFDR trace by utilizing intentional beat signals. This innovative approach simplifies hardware configuration, reduces system costs, and minimizes data acquisition time and computational load by eliminating the need for extra detection components. The proposed OFDR system is validated through simulations and experiments using 15 m and 100 m optical fibers, effectively compensating for nonlinear tuning effects. Furthermore, distributed temperature sensing demonstrates high spatial resolution and robust performance. This cost-efficient solution represents a significant advancement in nonlinearity compensation for OFDR systems, paving the way for broader adoption in fiber-optic sensing applications.