Utilization of NI PXIe-4844 interrogator for high resolution fiber extrinsic Fabry-Perot interferometric sensing

An advanced method of fiber extrinsic Fabry-Perot interferometer (EFPI) optical path difference (OPD) measurement with the use of the interrogator NI PXIe-4844 was applied for high precision distance, pressure and temperature measurements with resolutions up to 14 pm, 0.2 Pa and 2 mK respectively. Sub-nanometer resolution in multiplexed schemes was attained with single interrogating channel: from 30 to 80 pm for serial scheme with three sensors and from 40 to 200 pm for parallel scheme with four sensors. An ability to register the oscillating signals with frequencies up to 1000 Hz was demonstrated.