Optical time-domain reflectometry (OTDR) signals of step-index plastic optical fibers (POF’s) and graded-index POF’s were measured with a laser diode and an avalanche photodiode. When bent step-index and graded-index POF’s were used, the OTDR signal behavior differed. The OTDR signal of the bent graded-index POF’s had a step that corresponds to a curvature loss, but the step-index POF’s had a spike signal at a bend, which indicated the occurrence of backscattering. The peak intensity was proportional to the square of the curvature. The refractive-index variation of the bent step-index POF’s was measured, and the dependence of the peak intensity on the curvature was shown to agree with that predicted by the scattering from the refractive-index perturbation.
© 2001 Optical Society of America
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.2300) Fiber optics and optical communications : Fiber measurements
(120.5820) Instrumentation, measurement, and metrology : Scattering measurements
Tatsuya Sugita, "Optical Time-Domain Reflectometry of Bent Plastic Optical Fibers," Appl. Opt. 40, 897-905 (2001)