| One of the attractive techniques for sensor measurement is White LightInterferometry (WLI) that maintains the accuracy of monochromatic interferometry andavoids many of the limitations and problems associated with conventional interferencetechnique. The advantage of the white light interferometry is that absolute fiber opticelongation or deformation can be measured. Another advantage is the ability to coherencemultiplex many sensors onto a single optical signal without requiring the use of relativelycomplex time or frequency multiplexing techniques.Optical fiber sensor multiplexing method could reduces the cost per sensor bydesigning a system that minimizes the system components (sources, spectrometers, etc.). Themarket for multiplexed optical sensors is growing as fiber optic sensors are findingapplication in automated factories, mines, offshore platforms, air, sea, land, and spacevehicles, energy distribution systems, medical patient surveillance systems, etc.Multiplexed sensor system is usually called a quasi-distributed sensing system in whichone use a common interrogation system to simultaneously monitor the measurands at differentlocations. Many kinds of fiber sensor multiplexing technologies have been developed,including time division multiplexing (TDM), frequency division multiplexing (FDM),wavelength division multiplexing (WDM), coherence multiplexing (CM), code divisionmultiplexing (CDM), spatial division multiplexing (SDM) etc.In this thesis two configurations of fiber optic sensors network using white lightinterferometry are proposed and demonstrated, one is Ladder topology fiber optic sensorsnetwork, and the second is1XM coupler based fiber optic sensors network, The principle ofoperation, and the sensor networks systems are discussed, using a ASE light source power of1mW at a center wave length1310nm, experimental results that we got shows a capability ofmultiplexing an array of12sensors for the first case, and9sensors for the second topologyusing1X3star coupler. |
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