Measuring structural vibrations with a multimode fiber optical sensor

Advances in Optical Fiber Speckle Sensing: A Comprehensive Review

“…It should be mentioned that the use of the absolute value of the alternating signal (e.g., sine shape) leads to the doubling of signal spectrum width [37]. In works [69,70,75], authors applied a time differentiation of the camera pixel's signal. The work [76] demonstrates the results of the application of various image processing algorithms (both intensity-based and correlation-based) for speckle pattern processing.…”

Intrusion Detection System based on Speckle Pattern change in Fiber Optic Sensors

“…Each mode travels with its own group velocity and propagation constant, but interferes with other modes as they share the same medium. There are around 500 modes in a typical multimode fiber [5]. The speckle pattern inside the fiber can be detected by projecting it from the fiber ending upon a screen.…”

Intensity modulated silver coated glass optical fiber refractive index sensor

“…The special properties of being non-electrical, small in size, rugged, and immune to electromagnetic interference boost the use of optical fibers for sensing applications in the fields of engineering, science, and technology. The physical properties, such as temperature [5] , liquid level [6,7] , radiation [8] , strain, refractive index [9] , vibration [10] , concentration of liquid [11] , and chemical analysis [12] , can be detected by optical fiber sensors. Furthermore, low loss, low dispersion, ultra-wide bandwidth, high dynamic range, durability, upgradability, and low cost networks are other reasons for shifting the attention from traditional electrical sensors to optical fiber sensors.…”