EFPI signal processing method providing picometer-level resolution in cavity length measurement

2015 International Siberian Conference on Control and Communications (SIBCON)

Лиокумович

Medvedev

2015

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An advanced method of fiber extrinsic Fabry-Perot interferometer (EFPI) optical path difference (OPD) measurement with the use of the interrogator NI PXIe-4844 was applied for high precision distance, pressure and temperature measurements with resolutions up to 14 pm, 0.2 Pa and 2 mK respectively. Sub-nanometer resolution in multiplexed schemes was attained with single interrogating channel: from 30 to 80 pm for serial scheme with three sensors and from 40 to 200 pm for parallel scheme with four sensors. An ability to register the oscillating signals with frequencies up to 1000 Hz was demonstrated.Keywords-extrinsic Fabry-Perot interferometer, EFPI, fiber optic sensor, tunable laser, spectral measurements, multiplexing, signal processing, wavelength scanning interferometry, displacement measurement, pressure measurement, temperature measurement, spectral interferometery

Section: Extrinsic Fabry-perot Interferometermentioning

confidence: 98%

Section: Multiplexed Sensorsmentioning

confidence: 99%

Utilization of NI PXIe-4844 interrogator for high resolution fiber extrinsic Fabry-Perot interferometric sensing

2015 International Siberian Conference on Control and Communications (SIBCON)

Лиокумович

Medvedev

2015

Self Cite

“…One of the most attractive approaches for estimation of the baseline L from the registered spectrum S'(λ) is to approximate it with known analytical expression describing the interferometer transfer function S(λ, L) by means of least-squares fitting 12,13 . Such fitting returns the global minimum of the residual norm, which is given by the expression…”

Section: Wavelength-domain Interrogation Of Fabry-perot Interferometermentioning

confidence: 99%

Optical properties of metallic nanoparticles trapped by arabinogalactan molecule

Radchuk

Photonics, Devices, and Systems VI

2015

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“…Such sensors demonstrate great dynamic measurement range and high resolution [2,3]. Sensors of significant variety of physical quantities have been designed and implemented.…”

Section: Introductionmentioning

confidence: 99%

“…Among them are the so-called "frequency-estimating" [7,12], which are based on the analysis of the oscillation frequency of S 0 λ fringes, and the so-called "phase-estimating" [12][13][14], evaluating the argument of the S 0 λ fringe oscillations; and the approximation-based [3,6], approximating the S 0 λ with analytical expression in Eq. (1) by means of a least-squares fitting.…”

Section: Introductionmentioning

confidence: 99%

Enhancing the resolution limits of spectral interferometric measurements with swept-wavelength interrogation by means of a reference interferometer

2015

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An approach for compensating the influence of interrogator noises on the readings of interferometric sensors, interrogated by means of spectral interferometry with wavelength tuning, is proposed. Theoretical analysis and a proof-of-principle experiment were performed for the example of extrinsic Fabry-Perot interferometers. Two schemes, comprised of a signal and reference interferometers, switched in different optical channels of the interrogating unit, were proposed. The approach is based on the fact that the fluctuations of some of the interrogator parameters produce correlated fluctuations of the reference and signal interferometers' optical path differences' (OPDs) measured values. The fluctuations of the reference interferometer's measured OPD can be subtracted from the measured OPD of the signal interferometer. The fluctuations of different parameters of the interrogator are considered, the correlation properties of the produced noises of the measured OPD values are demonstrated. The first scheme contains two interferometers with similar parameters and enabled a threefold resolution improvement in the performed experiments, when the difference of the interferometers OPDs was varied within about 10 nm. The second scheme contains two interferometers with OPDs difference such that all interrogator fluctuations, except for the dominating one, produce uncorrelated OPD errors. With the second scheme, a twofold resolution improvement was experimentally demonstrated when the interferometers' OPDs difference was varied within more than 1 μm. The proposed approach can be used for improving the resolution of interferometric sensors with relatively large OPDs (greater than 200-300 μm), which can be advantageous for remote materials and surface inspection. The other potential application is the use of relatively simple cheap interrogators with poor wavelength scale repeatability for high-precision measurements.