The optical fiber fault detection by computer simulation for OFDR system

الملخص EN

Mathematical simulation and theoretical investigation for faults detection in optical fibers were discussed by using computer simulation.

The purpose of this work is to detect the faults that lead to decrease the level of the signal of the single mode fiber (SMF) for a length of (20km) for two wavelengths (1310nm & 1550nm) with attenuation of (0.34dB / km & 0.2dB / km) respectively by using Optical Frequency Domain Reflectometer (OFDR).

The fusion splice is assumed to be existent about (5km),the connector about (10km) and the bend about (15km).

The losses of these splices, bends, connectors and the levels of the reflected signals from the beginning of the fiber to its end have been calculated for two wavelengths.

The calculation of the reflected signals by OFDR system has shown high resolution.

the attenuation of wavelength (1550) nm is less than (1310) nm especially in the long distances (Z  15km), where the bending leads to big attenuation for the wavelength (1550) nm than (1310) nm where the level of the reflected signals at the point of bending for wavelength (1550) nm was (-87.852dBm) and (-80.2dBm) for the wavelength (1310nm).

A novel technique was used to detect the fault by (phase method) by using OFDR system, The degree of the phase is changing suddenly for the reflected signals in the places where the faults are happening.

The phase degree increases with the increase of the fiber length.