High-resolution fibre-grating based strain sensor with interferometric wavelength-shift detection

Multi-Channel Adaptive Interferometers Based on Dynamic Hologram Multiplexing

“…Spectrometric methods (Davis & Kersey, 1995) suffer from low sensitivity and are not suitable for dynamic measurements if several sensors have to be active at all times. Interferometric methods such as the Mach-Zehnder interferometer (Kersey, et al, 1992) are ideally suited to monitor dynamic strains; however, they require electronic feedback to actively compensate for any quasi-static drift to maintain the interferometer at quadrature. This makes the cost of multiplexing high since each sensor requires its own feedback system.…”

“…It is noteworthy that a similar principle of spectra change transformation to phase modulation is used as well in Mach-Zehnder and other unbalanced interferometers (Kersey, et al, 1992). From Eq.…”

Passive All-Fiber Wavelength Measurement Systems: Performance Determination Factors

“…Most of the passive devices are linearly wavelength dependent devices such as bulk edge filters (Mille et al, 1992), biconical fiber filters (Ribeiro et al, 1996), wavelength division couplers (Davis & Kersey, 1994), gratings (Fallon et al, 1999), multimode interference couplers etc. In active detection schemes the measurement depends on externally powered devices and examples of these schemes include those based on tunable filters (Kersey et al, 1993) and interferometric scanning methods (Kersey et al, 1992).…”

Distributed fiber optic interferometric geophone system based on draw tower gratings

“…Compared with traditional geophones, the fiber Bragg grating (FBG) geophone owns many advantages, such as immunity to electromagnetic interference, remote sensing, and multiplexing capacity, which makes FBG particularly suitable for multipoint sensing [5]. The FBG accelerometer can receive the acceleration with the help of wavelength demodulation schemes such as scanning Fabry-Perot filters [6], edge filter methods [5,7], or interferometric techniques [8]. An eight-element fiber laser geophone array system was presented in [9].…”