Radiophotonics amplitude-phase interrogation methods of complexed sensors based on fiber Bragg gratings
Abstract
Radiophotonics amplitude-phase interrogation methods of complexed sensors based on fiber Bragg gratings
Incoming article date: 08.04.2016The principles of construction of the interrogator for fiber optic sensors based on Bragg gratings, implementing radiophotonics measuring conversion technology on the principle of "optical wavelength - the amplitude and phase of a radio signal - measured value" are concerned. Their comparison with classical opto-electronic and radio photonic interrogator, implementing technology measurement conversion on the principle of "optical wavelength - radio frequency - the measured value" are produced. It is shown that the opto-electronic interrogator have significant limitations on resolution and interrogation speed and difficulty of simultaneous measurement of multiple, complexed to at least two measured values. Radiophotonic frequency interrogator, built on the basis of interferometers with additional dispersion conversion "rate - time" or optoelectronic oscillators allow to overcome the drawbacks of optoelectronic, but characterized by the complexity of the implementation of schemes of measuring conversion shift of the center wavelength of the grating in the information of unknown frequency. Radiophotonic amplitude-phase interrogator which is working at a known frequency - radio frequency envelope of the beat between the components of the two-frequency probe radiation signal, are proposed. This technique allows to exclude from the measurement process information search procedure of unknown frequency or amplitude of the maximum reflection of the FBG, which improves the speed and resolution of interrogation. Experimental results are presented to verify the procedure.
Keywords: fiber optic sensor, fiber Bragg grating, optoelectronic interrogator, radiophotonika, opto-electronic oscillator, measuring conversion type "optical wavelength - the frequency of the radio signal - measured value", measuring conversion type "optical wavel