The influence of the degree of coherence of a semiconductor laser on the statistic of the backscattered intensity in a single-mode optical fiber

Abstract

The results of the study of the statistical dependence of the backscattered light intensity of a semiconductor laser in a single-mode fiber on the duration of the probing pulse and the source coherence time are presented. It is shown that, for a given light coherence time, the intensity distribution function changes with increasing pulse duration from the function close to the exponential one for the pulse duration approximately equal to the coherence time to the function close to the Gaussian one for the pulse duration exceeding the coherence time. The exponential statistics of scattered light makes it possible to obtain a higher sensitivity for the coherent reflectometer using the direct detection method.