Optical Time Domain Reflectometer for Single-Mode Fibers

Tsuneo HORIGUCHI  Masamitsu TOKUDA  

IEICE TRANSACTIONS (1976-1990)   Vol.E67   No.9   pp.509-515
Publication Date: 1984/09/25
Online ISSN: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Transmission Systems

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An optical time domain reflectometer for single-mode fibers has been designed and constructed at a 1.3 µm wavelength. A fast digital averager enables 44 dB signal-to-noise ratio improvement within about 40 seconds. Curve fitting by a least squares method reduces the variation in fiber loss measurements. By using an acoustooptical directional coupler, Fresnel reflection is removed. In addition, backscattered signal fluctuation caused by polarization fluctuation is suppressed to a negligible extent. Current drift in receiving circuits is decreased by using a drift compensation circuit. The optical time domain reflectometer that has been built can locate breaks in single-mode fibers with attenuations as high as 17.5 dB.