An Optimized Self-Compensated Solution for Temperature and Strain Cross-Sensitivity in FBG Interrogators Based on Edge Filter

Optical fiber sensors based on fiber Bragg gratings (FBGs) are prone to measurement errors if the cross-sensitivity between temperature and strain is not properly considered. This paper describes a self-compensated technique for canceling the undesired influence of temperature in strain measurement. An edge-filter-based interrogator is proposed and the central peaks of two FBGs (sensor and reference) are matched with the positive and negative slopes of a Fabry–Perot interferometer that acts as an optical filter. A tuning process performed by the grey wolf optimizer (GWO) algorithm is required to determine the optimal spectral characteristics of each FBG. The interrogation range is not compromised by the proposed technique, being determined by the spectral characteristics of the optical filter in accordance with the traditional edge-filtering interrogation. Simulations show that, by employing FBGs with optimal characteristics, temperature variations of 30 °C led to an average relative error of 3.4% for strain measurements up to 700μϵ. The proposed technique was experimentally tested under non-ideal conditions: two FBGs with spectral characteristics different from the optimized results were used. The temperature sensibility decreased by 50.8% as compared to a temperature uncompensated interrogation system based on an edge filter. The non-ideal experimental conditions were simulated and the maximum error between theoretical and experimental data was 5.79%, proving that the results from simulation and experimentation are compatible.

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Research on Terahertz Filters Employing the Effect of Frustrated Total Internal Reflection

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.437.281 ◽

2010 ◽

Vol 437 ◽

pp. 281-285

Author(s):

Aleksandra S. Syrneva ◽

Vladimir V. Chesnokov ◽

Dimitry V. Chesnokov

Keyword(s):

Spectral Region ◽

Total Internal Reflection ◽

Spectral Characteristics ◽

Optical Filter ◽

Internal Reflection ◽

Frustrated Total Internal Reflection ◽

Input And Output ◽

Fabry Perot ◽

Micromechanical Device

The optical filter under development employing frustrated total internal reflection is a micromechanical device containing two silicon rectangular prisms. There is flat silicon plane among hypotenuse edges of the prisms. The silicon plane is a Fabry-Perot resonator, with clearances h1 among the plate and prism edges being its mirrors. Theoretical resolution of the optical filter would be R ≈ 1,5∙103 if h1 = 50 µm and R ≈ 3∙105 if h1 = 100 µm with the thickness of the silicon plane being h = 65 µm; wavelength λ = 100 µm; free spectral region Δλ/λ ≈ 0,3…0,4, transmission in the maximum of spectral characteristics 0,6 (provided input and output silicon prism legs bloom).

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Analysis of Dielectric Waveguide Grating and Fabry–Perot Modes in Elastic Grating in Optical Detection of Ultrasound

Sensors ◽

10.3390/s21124081 ◽

2021 ◽

Vol 21 (12) ◽

pp. 4081

Author(s):

Suejit Pechprasarn ◽

Chayanisa Sukkasem ◽

Phitsini Suvarnaphaet

Keyword(s):

Optical Properties ◽

Dielectric Waveguide ◽

Figure Of Merit ◽

Pressure Range ◽

Optical Filter ◽

Grating Period ◽

Wave Mode ◽

Waveguide Grating ◽

Fabry Perot ◽

Optical Grating

In our previous work, we have demonstrated that dielectric elastic grating can support Fabry–Perot modes and provide embedded optical interferometry to measure ultrasonic pressure. The Fabry–Perot modes inside the grating provide an enhancement in sensitivity and figure of merit compared to thin film-based Fabry–Perot structures. Here, in this paper, we propose a theoretical framework to explain that the elastic grating also supports dielectric waveguide grating mode, in which optical grating parameters control the excitation of the two modes. The optical properties of the two modes, including coupling conditions and loss mechanisms, are discussed. The proposed grating has the grating period in micron scale, which is shorter than the wavelength of the incident ultrasound leading to an ultrasonic scattering. The gap regions in the grating allow the elastic grating thickness to be compressed by the incident ultrasound and coupled to a surface acoustic wave mode. The thickness compression can be measured using an embedded interferometer through one of the optical guided modes. The dielectric waveguide grating is a narrow bandpass optical filter enabling an ultrasensitive mode to sense changes in optical displacement. This enhancement in mechanical and optical properties gives rise to a broader detectable pressure range and figure of merit in ultrasonic detection; the detectable pressure range and figure of merit can be enhanced by 2.7 times and 23 times, respectively, compared to conventional Fabry–Perot structures.

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Optimization of Single-/Multi-/Single-Mode Intrinsic Fabry–Perot Fiber Sensors

Journal of Lightwave Technology ◽

10.1109/jlt.2012.2195475 ◽

2012 ◽

Vol 30 (14) ◽

pp. 2281-2288 ◽

Cited By ~ 7

Author(s):

Cheng Ma ◽

Bo Dong ◽

E. M. Lally ◽

Anbo Wang

Keyword(s):

Single Mode ◽

Fiber Sensors ◽

Fabry Perot

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Electrically tunable optical filter for infrared wavelength using liquid crystals in a Fabry–Perot étalon

Applied Physics Letters ◽

10.1063/1.104045 ◽

1990 ◽

Vol 57 (17) ◽

pp. 1718-1720 ◽

Cited By ~ 102

Author(s):

J. S. Patel ◽

M. A. Saifi ◽

D. W. Berreman ◽

Chinlon Lin ◽

N. Andreadakis ◽

...

Keyword(s):

Liquid Crystals ◽

Optical Filter ◽

Infrared Wavelength ◽

Tunable Optical Filter ◽

Fabry Perot

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Gravity-Based Characterization of Three-Axis Accelerometers in Terms of Intrinsic Accelerometer Parameters

Journal of Research of the National Institute of Standards and Technology ◽

10.6028/jres.122.032 ◽

2017 ◽

Vol 122 ◽

Cited By ~ 4

Author(s):

Jon Geist ◽

Muhammad Yaqub Afridi ◽

Craig D. McGray ◽

Michael Gaitan

Keyword(s):

Gravitational Field ◽

Coordinate System ◽

Measurement Errors ◽

Angle Measurement ◽

Sensitivity Matrix ◽

Cross Sensitivity ◽

Measurement Capability ◽

Intrinsic Parameters ◽

The Cross ◽

Alignment Errors

Cross-sensitivity matrices are used to translate the response of three-axis accelerometers into components of acceleration along the axes of a specified coordinate system. For inertial three-axis accelerometers, this coordinate system is often defined by the axes of a gimbal-based instrument that exposes the device to different acceleration inputs as the gimbal is rotated in the local gravitational field. Therefore, the cross-sensitivity matrix for a given three-axis accelerometer is not unique. Instead, it depends upon the orientation of the device when mounted on the gimbal. We define nine intrinsic parameters of three-axis accelerometers and describe how to measure them directly and how to calculate them from independently determined cross-sensitivity matrices. We propose that comparisons of the intrinsic parameters of three axis accelerometers that were calculated from independently determined cross-sensitivity matrices can be useful for comparisons of the cross-sensitivity-matrix measurement capability of different institutions because the intrinsic parameters will separate the accelerator-gimbal alignment differences among the participating institutions from the purely gimbal-related differences, such as gimbal-axis orthogonality errors, z-axis gravitational-field alignment errors, and angle-setting or angle-measurement errors.

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Investigation of a Fabry-Perot-based optical filter for broadband multichannel communication systems

10.1117/12.851247 ◽

2009 ◽

Author(s):

Jinrong Zhang ◽

Yubin Guo ◽

Jiayu Huo ◽

Gang Wang ◽

Shuming Zhang

Keyword(s):

Communication Systems ◽

Optical Filter ◽

Fabry Perot

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DISTORTIONLESS SIGNALS TRANSFER THROUGH A WIRE MEDIA METASTRUCTURE

Informatyka Automatyka Pomiary w Gospodarce i Ochronie Środowiska ◽

10.5604/01.3001.0010.8646 ◽

2018 ◽

Vol 8 (1) ◽

pp. 44-47 ◽

Cited By ~ 2

Author(s):

Dmytro Vovchuk ◽

Serhii Haliuk ◽

Leonid Politanskyy

Keyword(s):

Electromagnetic Waves ◽

Spectral Characteristics ◽

Wide Frequency Range ◽

Power Transfer ◽

Fabry Perot ◽

Signal Distortions ◽

Metallic Wires ◽

The Wire ◽

Wire Media ◽

First Time

In the paper the development of the components of communication means is considered based on the wire metastructures. This approach is novel and quite promising due to the metamaterials provides new opportunities for the radio engineering devices such as antennas, absorbers etc. First of all it makes possible decreasing of the dimensions of devices while the characteristics stay the same or better. Here the artificially created metastructure that consists of parallel metallic wires and characterizes by a negative electric permittivity was investigated. The possibility of broadband power transfer of electromagnetic waves was demonstrated. Also, at first time, the investigation of possible signal distortions due to wave propagation through the wire medium (WM) slab was performed via analyzing of spectral characteristics. The obtained results allow applying of WM to power transfer in wide frequency range (not only at frequencies of Fabry-Perot resonant) and enhancement of weak source propagation as well as to antennas constructions due to the absence of signal distortions. One of the promising applications of such structures is the possibility of realizing of flexible screens with nanometer thickness and high resolution.

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Quantitative Retrieval of Tidal Flat Moisture Based on TM Images

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.1066 ◽

2013 ◽

Vol 448-453 ◽

pp. 1066-1071

Author(s):

Li Jun Yang ◽

Ming Fei Wu ◽

Yun Hong Zhu

Keyword(s):

Remote Sensing ◽

Relative Error ◽

Tidal Flat ◽

Spectral Characteristics ◽

Atmospheric Correction ◽

Maximum Error ◽

Exponential Model ◽

Wave Band ◽

Gradient Distribution ◽

Distribution Features

Based on spectrometry, the remote sensing inversion researches of the surface tidal flat moisture are conducted in combination with spectral values measured in the field and moisture measured in the laboratory. Firstly, the remote sensing images are preprocessed, including geometric correction, atmospheric correction and image enhancement. Then, the spectral characteristics of typical ground objects are analyzed to partition the whole image and separate the bare tidal flats. At last, TM5 wave band and exponential model are determined to be the best wave band and optimal model for the inversion of the bare tidal flat moisture. The experiment shows: (1)This method can help to improve the accuracy of the surface tidal flat moisture inversion, with the maximum error of moisture inversion is 3%, the relative error is 7.1% and the average relative error is 6.5%. (2)The surface tidal flat moisture is of evident gradient distribution features, which can be used as basis of tidal flat topographic survey.

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