Strength properties of femtosecond-induced defects and weak Bragg gratings for distributed optical fiber sensors

Abstract

One of the possible ways to increasing the sensitivity of distributed fiber sensors is to create point defects or weak Bragg gratings in a sensitive optical fiber serving as artificial reflectors. Such reflectors can be created by means of femtosecond laser radiation. However, after the inscribing such structures, a noticeable decrease in the mechanical reliability of the sensor fiber can be observed, which can be critical for the fabrication and operation of sensor cables. The paper reports the results of a study of the point defects and weak fiber Bragg gratings strength characteristics created for distributed sensor systems, depending on the parameters of the laser radiation used to inscribe them.