Simultaneous spatial, time and wavelength division multiplexed in-fibre grating sensing network

Optical fiber sensors: a route from University of Kent to Portugal

“…The work originated the first FBG British patent (GB2268581) for the group. The results were very encouraging, and the PhD work continued to progress after that year, with different FBG demodulation schemes [12] and several combinations of optical multiplexing schemes (wavelength division multiplexing + spatial division multiplexing + time division multiplexing) were for the first time demonstrated [13,14].…”

Study on fiber-optic low-coherence interferometric and fiber Bragg grating sensors

“…We have proposed a series of multiplexing techniques for FBG sensors based on SDM, WDM, TDM, and their combinations [42][43][44][45][46][47][48][49][50]. Special efforts were under taken to improve the multiplexing capacity and SNR as well as to reduce the cross-talk of the system.…”

“…29 [44,45]. Both the tunable F-P filter (FPF) and the interferometric wavelength scanner (IWS) are combined in tandem and are located immediately after the broadband source rather than in front of the detector to allow all the FBG elements with similar wavelengths on all the fiber sensing channels to be interrogated simultaneously.…”

<title>Study on the demodulation technique of fiber grating sensor arrays based on a tunable pulsed laser</title>

“…Multi-point detection can be realized by using lots of FBGs to compose of sensor net, which has a great application value for the smart materials and structure. Several ways of multiplexing these sensors have been proposed [3][4][5][6][7][8], TDM technique is a better way to enlarge the measuring points, but the demodulation technique for the sensor signals limits its' development, so seeking a simple, inexpensive and effective demodulation technique is the key for TDM FBG Sensor Arrays. In this paper, TDM demodulation technique of FBG sensor arrays using a tunable pulsed laser is studied.…”