New matrix solution of the phase-correlation technique in a Brillouin dynamic grating sensor

Mansoursamaei²,

Pashaie

2021

Opt Quant Electron

Self Cite

Many efforts have been devoted to simultaneous measurements of strain and temperature by FBG sensors and several improving techniques have been resulted and implemented on the measurement. Most of them are based on two or more FBGs configurations or a single non-uniform FBG implementation. We propose simultaneous measurement of temperature and strain based on peak power changes and Bragg wavelength shifts using only one uniform fiber Bragg grating (FBG). We placed a ramp with the angle of θ, similar to a tilted cantilever beam, on an assumptive structure and stuck a uniform FBG on it. When a uniform strain applied to a structure, the cantilever beam converts it to a non-uniform strain distribution along with itself and consequently the uniform FBG. By creating this non-uniform strain distribution, the peak power of the reflection spectrum of the FBG will be sensitive to strain changes. In addition, the Bragg wavelength shift will be sensitive to both temperature and strain parameters. According to our simulation, temperature sensitivity of 14.15 pm/℃ is obtained for FBG sensor without any changes in the peak power. The strain sensitivity of 0.7837 pm/με, and a nonlinear sensitivity according to a quadratic function for peak power variation are also observed.

“…Figure (4): Relationship between ∆P and the strain applied to the structure Equation (4) shows the relationship between maximum ∆P and the applied strain to the structure:…”

Section: Measurement Of Strain In Tilted Cantilever Beammentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous measurement of temperature and strain based on peak power changes and wavelength shift using only one uniform fiber bragg grating

Mansoursamaei²,

Pashaie

2021

Opt Quant Electron

Self Cite

“…4, the relationship between the Maximum ∆P and this strain is nonlinear. Equation (4) shows the relationship between maximum ∆P and the applied strain to the structure:…”

Section: Measurement Of Strain In Tilted Cantilever Beammentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous Measurement of Temperature and Strain Based on Peak Power Changes and Wavelength Shift Using Only One Uniform Fiber Bragg Grating

Mansoursamaei

Pashaie

2021

Preprint

Self Cite

Many efforts have been devoted to simultaneous measurements of strain and temperature by FBG sensors and several improving techniques have been resulted and implemented on the measurement. Most of them are based on two or more FBGs configurations or a single non-uniform FBG implementation. We propose simultaneous measurement of temperature and strain based on peak power changes and Bragg wavelength shifts using only one uniform fiber Bragg grating (FBG). We placed a ramp with the angle of θ, similar to a tilted cantilever beam, on an assumptive structure and stuck a uniform FBG on it. When a uniform strain applied to a structure, the cantilever beam converts it to a non-uniform strain distribution along with itself and consequently the uniform FBG. By creating this non-uniform strain distribution, the peak power of the reflection spectrum of the FBG will be sensitive to strain changes. In addition, the Bragg wavelength shift will be sensitive to both temperature and strain parameters. According to our simulation, temperature sensitivity of 14.15 pm/℃ is obtained for FBG sensor without any changes in the peak power. The strain sensitivity of 0.7837 pm/µε, and a nonlinear sensitivity according to a quadratic function for peak power variation are also observed.

“…These sensors have several potential bene ts that make them attractive for a variety of sensing applications. They are typically small in size, immune to electromagnetic interference, passive, resistant to harsh environments, and can perform distributed sensing [8][9][10][11]. Among optical ber sensors, ber Bragg grating (FBG) has found many applications due to its ability to measure all environmental parameters such as temperature, strain, stress, bending, humidity, etc.…”

Section: Introductionmentioning

confidence: 99%

Comparison of FWHM and peak power of FBG spectrum for simultaneous measurement of strain and temperature based on tilted cantilever beam

Mansoursamaei

Gholampour

2022

Preprint

Self Cite

Among the optical fiber sensors, fiber Bragg grating (FBG) has found remarkable attraction and many applications due to its ability to measure all environmental parameters, high accuracy and sensitivity, easy installation, and low price. The sensor's ability to simultaneous measurement of two environmental (physical) parameters, especially strain and temperature, has made it even more demanding. Recently, two techniques based on FWHM and peak power changes of FBG spectrum have been proposed for simultaneous measurement of temperature and strain that use a uniform FBG on a tilted cantilever beam. In this article, we evaluate and compare both techniques and demonstrate that both are equivalent and have almost similar behaviour but do not have the same applications. We find that at the low strain range the peak power technique is more accurate while at the high strain range the FWHM technique has better accuracy. Therefore, in applications such as monitoring civil structures that have a high strain range, it is better to use the FWHM technique and in some delicate industrial applications with a low strain range, the peak power technique is used.