TY - JOUR N2 - In this paper, we present a fibre-optic sensor for simultaneous measurement of refractive index and thickness of liquid layers.We designed an experimental low-coherence setup with two broadband light sources and an extrinsic fibre-optic Fabry–Pérot interferometer acting as the sensing head.We examined how the refractive index of a liquid film and its thickness affect spectrum at the output of a fibre-optic interferometer. We performed a series of experiments using two light sources and only one sensing head. The spectra were collected in ranges of 1220÷1340 nm and 1500÷1640 nm. The obtained results show that using two spectra recorded simultaneously for two wavelength ranges enables to determine thickness in a range of 50÷500 μm, and refractive index of a liquid film in a range of 1:00÷1:41 RIU using only one sensing head. L1 - http://www.czasopisma.pan.pl/Content/113103/PDF/10_MMS_3_INTERNET.pdf L2 - http://www.czasopisma.pan.pl/Content/113103 PY - 2019 IS - No 3 EP - 568 DO - 10.24425/mms.2019.129584 KW - fibre-optic KW - sensors KW - interferometry KW - Fabry–Pérot interferometer A1 - Marzejon, Marcin A1 - Karpienko, Katarzyna A1 - Mazikowski, Adam A1 - Jędrzejewska-Szczerska, Małgorzata PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation VL - vol. 26 DA - 2019.09.23 T1 - Fibre-optic sensor for simultaneous measurement of thickness and refractive index of liquid layers SP - 561 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/113103 T2 - Metrology and Measurement Systems ER -