METHOD OF DETECTING SIGNALS OF MEASURING TRANSDUCERS BASED ON BRAGG GRATINGS, RECORDED IN SINGLE FIBRE OPTICAL GUIDE

摘要

FIELD: physics.;SUBSTANCE: optical reflectometre generates a probing pulse which falls on a first examined Bragg grating through a circulator. Part of the probing pulse is reflected from the grating and falls on reference gratings whose reflection spectra lie equidistant from the spectrum of the examined Bragg grating. Two reflected signals are generated, having power which is determined by the spectral interval between the spectrum of examined grating and the spectrum of the corresponding reference grating. Reflected signals are returned to the reflectometre and are displayed on a reflectogram in form of two peaks whose amplitude is proportional to the power of these signals. The spectrum of the examined grating shifts in case of an external physical effect. One of the peaks increases while the other falls. The difference between the amplitude of these peaks is the picked up signal. In order to pick up signals of the next groups of examined fibre Bragg gratings, the reference Bragg gratings are rearranged so that the initial resonance wavelengths of the examined fibre Bragg gratings are exactly between the resonance wavelengths of reference Bragg gratings.;EFFECT: wider measurement range and high resistance to amplitude noise.;8 dwg