High-spatial-resolution OFDR with single interferometer using self-compensation method

Abstract

A high-spatial-resolution optical frequency domain reflectometry (OFDR) with single interferometer was proposed by using self-compensation method (SCM). The auxiliary interferometer (AI) of conventional OFDR was replaced by a processed arc end of the fiber under test (FUT) to generate a reflection signal with appropriate intensity. The actual instantaneous optical frequency (IOF) was successfully extracted from the arc end of the FUT. Combining the arc end and SCM, the phase noise of the proposed OFDR was successfully eliminated to obtain the compensated signal with high signal-to-noise ratio (SNR). Moreover, the influence of delay fiber (DF) length on the compensation effect was theoretically and experimentally analyzed. The proposed OFDR achieved the distributed temperature sensing with a high-spatial-resolution of 3 mm without sacrificing measurement performance, where the measured distance of the FUT was ∼ 108 m. The high-spatial-resolution of 5 mm was still achieved when the measured distance of the FUT was increased to ∼170 m. Such an OFDR system with low cost and good performance has development potential in the field of distributed measurement.