&lt;title&gt;Digital demodulation of a twin-grating fiber optic sensor&lt;/title&gt;

Miridonov, Serguei V.; Shlyagin, Mikhail G.; Tentori, Diana

doi:10.1117/12.339102

Cited by 15 publications

(21 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the calibration, there are four steps: (1)

R_{T} (λ)

is acquired, (2)

R_{T} (ν)

is computed, (3)

R_{m} (ν)

is filtered

R_{m} (ν) = R_{T} (ν) F (ν),

and (4) we calculate its complex conjugate

R_{m}^{*} (ν)

where * indicates a complex conjugate. In the measurement, there are seven steps: (1)

R_{T} (λ, δ λ)

is acquired, (2)

R_{T} (ν, δ λ)

is computed, (3)

{\tilde{R}}_{m} (ν, δ λ)

is filtered

{\tilde{R}}_{m} (ν, δ λ) = R_{T} (ν, δ λ) F (ν)

, (4) the relative phase

φ_{r e l}

is calculated, (5) the ambiguity

2 π P

is eliminated and then absolute phase

φ_{a b s}

is calculated, (6), the Bragg wavelength shift is computed, and (7) a digital adaptive filter is applied [37]. …”

Section: Digital Demodulationmentioning

confidence: 99%

A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing

Bonilla

Rodríguez-Betancourtt

et al. 2017

Sensors

View full text Add to dashboard Cite

The application of the sensor optical fibers in the areas of scientific instrumentation and industrial instrumentation is very attractive due to its numerous advantages. In the industry of civil engineering for example, quasi-distributed sensors made with optical fiber are used for reliable strain and temperature measurements. Here, a quasi-distributed sensor in the frequency domain is discussed. The sensor consists of a series of low-finesse Fabry-Perot interferometers where each Fabry-Perot interferometer acts as a local sensor. Fabry-Perot interferometers are formed by pairs of identical low reflective Bragg gratings imprinted in a single mode fiber. All interferometer sensors have different cavity length, provoking frequency-domain multiplexing. The optical signal represents the superposition of all interference patterns which can be decomposed using the Fourier transform. The frequency spectrum was analyzed and sensor’s properties were defined. Following that, a quasi-distributed sensor was numerically simulated. Our sensor simulation considers sensor properties, signal processing, noise system, and instrumentation. The numerical results show the behavior of resolution vs. signal-to-noise ratio. From our results, the Fabry-Perot sensor has high resolution and low resolution. Both resolutions are conceivable because the Fourier Domain Phase Analysis (FDPA) algorithm elaborates two evaluations of Bragg wavelength shift.

show abstract

“…In the calibration, there are four steps: (1)

R_{T} (λ)

is acquired, (2)

R_{T} (ν)

is computed, (3)

R_{m} (ν)

is filtered

R_{m} (ν) = R_{T} (ν) F (ν),

and (4) we calculate its complex conjugate

R_{m}^{*} (ν)

where * indicates a complex conjugate. In the measurement, there are seven steps: (1)

R_{T} (λ, δ λ)

is acquired, (2)

R_{T} (ν, δ λ)

is computed, (3)

{\tilde{R}}_{m} (ν, δ λ)

is filtered

{\tilde{R}}_{m} (ν, δ λ) = R_{T} (ν, δ λ) F (ν)

, (4) the relative phase

φ_{r e l}

is calculated, (5) the ambiguity

2 π P

is eliminated and then absolute phase

φ_{a b s}

is calculated, (6), the Bragg wavelength shift is computed, and (7) a digital adaptive filter is applied [37]. …”

Section: Digital Demodulationmentioning

confidence: 99%

A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing

Bonilla

Rodríguez-Betancourtt

et al. 2017

Sensors

View full text Add to dashboard Cite

show abstract

“…It is necessary to note that double Bragg grating technique allows multiplexing of point sensors based on combination of wavelength division multiplexing (WDM) and frequency division multiplexing (FDM) principle [5]. Recently, we have demonstrate this new multiplexing method for the twin Bragg grating sensor configuration, where we use a signal processing based on the phase evaluation of the interference component in reflection spectra [6]. Fig.…”

Section: Resultsmentioning

confidence: 98%

Differential double Bragg grating sensor for temperature-insensitive strain measurement

Spirin¹,

Shlyagin²,

Miridonov

et al. 2001

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

A novel differential double Bragg grating sensor for temperature-insensitive strain measurement is presented. The sensor consists of two identical weak measuring and reference gratings separated by some distance. The reference grating is placed inside the silica capillary that made it almost strain insensitive. The basic idea in differential double Bragg grating sensor is to measure the energy of the oscillating term in reflection spectrum of double Bragg grating structure. The normalized energy of the interference term depends on the pitch difference of two gratings and does not change when pitch variations of both gratings are equal with temperature variation. Therefore the normalized energy of the interference term can be used for the temperature-insensitive strain measurement.

show abstract

“…absolute measurements with interferometric resolution. Principle of operation, the signal processing algorithm together with results of initial experiments for verifying functionality of the sensor were presented [10], however experimental data proving ability to perform static strain measurements with high resolution have not been reported. Later, a similar approach based on FPI formed with two Bragg gratings has been proposed and demonstrated using a different experimental configuration [11].…”

Section: Introductionmentioning

confidence: 99%

Static strain measurement with submicro strain resolution and large dynamic range using twin grating Fabry-Perot sensor

Shlyagin¹,

Swart

Miridonov

et al. 2001

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

We present experimental results on testing a twin grating fiber optic sensor for measurement of static strain. The sensor is built with two identical Bragg gratings closely spaced in a single mode fiber. It produces a reflection spectrum modulated due to interference. Similar to traditional FBG sensors, strain of the fiber leads to the wavelength shift of the reflection spectrum. This shift can be determined precisely measuring phase changes for corresponding components of Fourier transform of the reflection spectrum. Such an approach allows an absolute strain measurement with an interferometric sensitivity. Resolution of 0.02ºC and 0.2 ZDV GHPRQVWUDWHG H[SHULPHQWDOO\ IRU WHPSHUDWXUH DQG VWDWLF VWUDLQ PHDVXUHPHQWV using a pair of 0.7mm long Bragg gratings with reflectivity of 1% each.

show abstract

<title>Digital demodulation of a twin-grating fiber optic sensor</title>

Cited by 15 publications

References 0 publications

A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing

A Theoretical Study and Numerical Simulation of a Quasi-Distributed Sensor Based on the Low-Finesse Fabry-Perot Interferometer: Frequency-Division Multiplexing

Differential double Bragg grating sensor for temperature-insensitive strain measurement

Static strain measurement with submicro strain resolution and large dynamic range using twin grating Fabry-Perot sensor

Contact Info

Product

Resources

About