The Optical Time Domain Reflectometer is a device used for fiber optic measurements and fault location. It uses the principle of time-domain reflection of light to obtain information such as attenuation and fault location in optical fibers.
The testing principle of OTDR can be divided into the following steps:
1. Send light pulse: OTDR sends a short pulse of light signal into the tested fiber. This light pulse is generated by the light source and transmitted through the fiber to the point under test.
2. Detecting the returning light signal: The light pulse is scattered with inhomogeneities, attenuation and faults in the fiber as it travels through the fiber. A portion of this scattered optical signal is returned to the OTDR device.
3. Measurement of Returned Light Signal: An optical detector is used to detect and measure the returned scattered light signal. The detectors record parameters such as intensity, time delay and waveform of the scattered light signal.
4. Analyze and Plot Reflection Curve: By analyzing the recorded scattered light signal, the OTDR can calculate information such as attenuation, fault location and reflectivity in the fiber. It will plot a reflection curve that represents the attenuation and scattering of the optical signal as it travels through the fiber.
5. Interpretation and location of faults: Based on the reflection curve, it can determine the type of faults present in the fiber, such as fiber breaks, bends, connection problems, and so on. At the same time, based on the position of the peaks or reflection peaks on the reflection curve, it is possible to locate where the fault occurred.
