Practical Coherent Otdr At 1.3 μm

Abstract

The performance of a coherent OTDR system operating at 1.3 µm is described. Two sources have been used -a Nd:YAG laser and a semiconductor laser with increased coherence. With the latter source, greater than 24 dB one way range has been achieved with accurate determination of fault magnitude.

Review of long wavelength single-mode optical fiber reflectometry techniques

“…This is an ideal behavior for a backscatter source, since it ensures a degree of fading, which, after averaging, causes the speckle-like appearance of the backscatter trace to be smoothed out. Using this source, Wright et al [46] demonstrated a heterodyne OTDR with a one-way range of approximately 24 dB. The system operating parameters were PL = -15 dBm, W = 2 ps.…”

Advances in optical time domain reflectometry

“…6. Heterodyne Detection: In the heterodyne detection method [30]- [32], signal light and local oscillator light are mixed in the photodetector, and the beat signal is detected ( Fig. 9) [31].…”