Resolution control of low-coherence optical time-domain reflectometer between 14 and 290 mu m

Abstract
A low-coherence OTDR that can control spatial resolution is demonstrated through the use of a new light source consisting of a superluminescent diode (SLD), an AR-coated LD booster amplifier, and two identical optical bandpass filters: one for truncating the SLD output, and the other for reducing amplified spontaneous emission. The resolution is changed from 14 to 290 mu m for single mode fibers by using filters with different bandwidths. Backscattering measurements are demonstrated for a fiber at three resolutions: 14, 44, and 290 mu m. The best dynamic range at 10 Hz detection bandwidth is found to be 18 dB at 290 mu m resolution.