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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.


Typical E-field vector displacement rotation sensors’ arrangements.
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sensors-17-00443-f016: Typical E-field vector displacement rotation sensors’ arrangements.

Mentions: Ideal, perfectly circular, linear birefringence free, and straight single-mode fiber is a one-dimensional equivalent of a homogenous and isotropic medium, except that it can confine and guide light from the transmitter to the receiver effectively. Ideal, circularly-symmetric and straight fiber cannot rotate or otherwise affect the polarization plane. For any polarization transformations to take place within the fiber, the circular symmetry must be broken, which results in the appearance of (weak or strong) birefringence(s). Short sections of straight, modern telecom single-mode fiber, like SMF-28, are actually a very good approximation of ideal circularly-symmetric fiber. A significant effort has been devoted to fiber production process optimization to remove any intrinsic birefringence from these fibers due to the polarization mode dispersion effects that otherwise affect telecom systems adversely. Thus, by placing a linearly polarized source at one side of a short and straight section of SMF, and a polarization analyzer on the other, rotational displacement between source and polarization analyzer can be determined by measuring E-field vector orientation incident at the polarization analyzer as shown, for example, in Figure 16a.


Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †
Typical E-field vector displacement rotation sensors’ arrangements.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

sensors-17-00443-f016: Typical E-field vector displacement rotation sensors’ arrangements.
Mentions: Ideal, perfectly circular, linear birefringence free, and straight single-mode fiber is a one-dimensional equivalent of a homogenous and isotropic medium, except that it can confine and guide light from the transmitter to the receiver effectively. Ideal, circularly-symmetric and straight fiber cannot rotate or otherwise affect the polarization plane. For any polarization transformations to take place within the fiber, the circular symmetry must be broken, which results in the appearance of (weak or strong) birefringence(s). Short sections of straight, modern telecom single-mode fiber, like SMF-28, are actually a very good approximation of ideal circularly-symmetric fiber. A significant effort has been devoted to fiber production process optimization to remove any intrinsic birefringence from these fibers due to the polarization mode dispersion effects that otherwise affect telecom systems adversely. Thus, by placing a linearly polarized source at one side of a short and straight section of SMF, and a polarization analyzer on the other, rotational displacement between source and polarization analyzer can be determined by measuring E-field vector orientation incident at the polarization analyzer as shown, for example, in Figure 16a.

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.