光频域反射仪（OFDR）具有高空间分辨率、高精度和高灵敏度等多种分布式传感能力，其在油气资源勘探、结构健康监测，以及医疗微创介入手术等多种场合展示出了巨大的应用潜力。然而，扫频非线性噪声、相干衰落噪声，以及光纤中微弱的瑞利后向散射信号是影响光频域反射仪性能的主要因素。本文介绍了光频域反射仪基本原理和波长、相位两种传感解调方法，详细阐述了多种抑制扫频非线性噪声和相干衰落噪声的方法，同时介绍了光频域反射仪在三维形状、大应变、高温、折射率等4个方面的传感应用进展。

The optical frequency domain reflectometer (OFDR) boasts distributed sensing capabilities, including high spatial resolution, precision, and sensitivity. This technology exhibits significant promise across diverse applications, ranging from oil and gas resource exploration to structural health monitoring and minimally invasive medical intervention surgery. Despite its merits, challenges such as sweep frequency nonlinear noise, coherent fading noise, and weak Rayleigh backscatter signals in optical fibers can impact the performance of optical frequency domain reflectors. This article elucidates the fundamental principles of optical frequency domain reflectors and expounds on two sensing demodulation methods: wavelength and phase. Additionally, it delves into various strategies for mitigating sweep frequency nonlinear noise and coherent fading noise. The discussion extends to the progress in sensing applications of optical frequency domain reflectors, encompassing three-dimensional shape, large strain, high temperature, refractive index, and other pertinent aspects.