MULTICHANNEL FIBER-OPTIC SYSTEM FOR DETECTING AND MEASURING PARAMETERS OF ACOUSTIC EMISSION SIGNALS Russian patent published in 2021 - IPC G01N29/14 

FIELD: acoustic emission parameters measurement.

SUBSTANCE: invention is intended for detecting and measuring parameters of acoustic emission signals by means of a fiber-optic system. The substance of the invention lies in the fact that the fiber-optic system for detecting and measuring the parameters of acoustic emission signals contains two laser diodes connected to a DWDM multiplexer, the output of which is connected to a fiber-optic splitter, each output of which is connected to the first port of the optical circulator, and a fiber-optic sensor, which is a fiber interferometer, is connected to the second port of the said circulator, the output of the optical circulator is connected to the DWDM demultiplexer, the outputs of the specified demultiplexer are connected to the inputs of two optical fiber photodetectors, wherein the operating wavelengths of the laser diodes are chosen so that the difference in their values is at least one period of the standard DWDM frequency grid, while the difference in the lengths of the interferometer arms is selected so that, when exposed to harmonic mechanical vibrations in the operating frequency range, the phase difference of voltage signals on at the outputs of fiber-optic photodetectors was π/2.

EFFECT: invention provides the possibility of simplifying the design of the fiber-optic system for detecting and measuring the parameters of acoustic emission signals and providing the possibility of creating a registration system that is insensitive to the drift of the cavity length.

1 cl, 2 dwg