OTDR emits light pulses and receives the backscattered light and reflected light signals generated when the light pulses propagate in the optical fiber. It determines the abnormal points in the optical fiber according to the changes in signal strength, thereby locating the breakpoints. The principle of measuring optical fiber breakpoints mainly includes the following steps:
Emitting light pulses: OTDR emits a light pulse through the optical fiber.
Rayleigh scattering: When the light pulse propagates in the optical fiber, it will encounter Rayleigh scattering, that is, part of the light will be randomly scattered in all directions, and part of the backscattered light will return to the OTDR.
Fresnel reflection: When the light pulse encounters a discontinuity in the optical fiber (such as a breakpoint, connector or end face), Fresnel reflection occurs, and part of the light is reflected back to the OTDR.
Signal analysis: OTDR receives and analyzes these returned scattered light and reflected light signals, determines the abnormal points in the optical fiber according to the changes in signal strength, thereby locating the breakpoint position