A new fiber-optic high hydrostatic pressure sensor up to 100 MPa based on extrinsic intensity modulation of light reflected from a cholesteric liquid crystal (ChLC) sensing element is proposed and demonstrated. The sensor exploits the effect of pressure-induced changes in the wavelength of maximum light reflection observed in ChLCs. Three different configurations of the sensor which utilizes multimode optical fibers for communication with the high-pressure region were investigated: a double-source configuration and two configurations with double sensing elements. Results obtained demonstrate that the proposed cost-effective fiber-optic liquid-crystal sensor has a pressure coefficient two orders of magnitude higher than current high-pressure sensors. Depending on the applied configuration, the sensor can display a good linear response and sensitivity for specific ranges of pressure useful in industrial applications.
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