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Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

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ABSTRACT

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.

No MeSH data available.


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An example of forward propagating spectrum in excessively tilted FBG and its spectral response; ratio of dips P1 and P2 changes with fiber rotation (CW/CCW).
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sensors-17-00443-f022: An example of forward propagating spectrum in excessively tilted FBG and its spectral response; ratio of dips P1 and P2 changes with fiber rotation (CW/CCW).

Mentions: The resonant wavelength at which coupling occurs between fundamental and particular cladding modes thus becomes split into two closely spaced resonances, each belonging to a particular polarization state. This polarization dependence is especially pronounced in excessively tiled gratings [94,97]. Rotation of the incident forward propagating E-field vector around the fiber axis therefore leads to periodic variation in coupling strength at resonant wavelengths as shown in Figure 22. The TFBG spectrum thus encodes information on the incident E-field orientation. For example, observation of coupling strength at a particular resonant wavelength (i.e., depth of an intensity dip in the transmission spectrum), or ratio of coupling strengths (ratio of intensity dips) belonging to two orthogonal E-field polarizations [94,95,97], thus carries information on the incident E-field direction relative to the TFBG tilt plane as, for example, shown in Figure 22.


Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †
An example of forward propagating spectrum in excessively tilted FBG and its spectral response; ratio of dips P1 and P2 changes with fiber rotation (CW/CCW).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5375729&req=5

sensors-17-00443-f022: An example of forward propagating spectrum in excessively tilted FBG and its spectral response; ratio of dips P1 and P2 changes with fiber rotation (CW/CCW).
Mentions: The resonant wavelength at which coupling occurs between fundamental and particular cladding modes thus becomes split into two closely spaced resonances, each belonging to a particular polarization state. This polarization dependence is especially pronounced in excessively tiled gratings [94,97]. Rotation of the incident forward propagating E-field vector around the fiber axis therefore leads to periodic variation in coupling strength at resonant wavelengths as shown in Figure 22. The TFBG spectrum thus encodes information on the incident E-field orientation. For example, observation of coupling strength at a particular resonant wavelength (i.e., depth of an intensity dip in the transmission spectrum), or ratio of coupling strengths (ratio of intensity dips) belonging to two orthogonal E-field polarizations [94,95,97], thus carries information on the incident E-field direction relative to the TFBG tilt plane as, for example, shown in Figure 22.

View Article: PubMed Central - PubMed

ABSTRACT

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.

No MeSH data available.


Related in: MedlinePlus