Authors
Abstract
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 ³15km), 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.
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