Shojaei Khatouni, SohrabSohrabShojaei KhatouniZakowski, SvenSvenZakowskiHosseini Vedad, RezaRezaHosseini VedadMasjedi, MustafaMustafaMasjediAskar, AkramAkramAskarEwald, Jan Christian EliJan Christian EliEwaldTrieu, Hoc KhiemHoc KhiemTrieu2024-07-092024-07-092024-07-08Journal of Sensors and Sensor Systems 13 (2): 147-155 (2024)https://hdl.handle.net/11420/48263This paper presents the development and evaluation of four sensors based on multiple fiber Bragg grating (FBG) constellations embedded in a silicon dioxide single-mode fiber (SMF) for simultaneous measurement of pressure, temperature, and bending curvature. We applied dimension and material variations – including core, cladding, and coating dimensions; coating material; and the number and arrangement of the FBGs – to optimize the reflected signal response and increase information density. A bootstrap-aggregated ensemble of decision trees was used to evaluate the sensor signal. The results show that adjusting the cladding-to-coating ratio led to significant improvements in pressure and bending prediction performance. Additionally, two combined FBGs were fabricated to form a fiber Bragg grating Fabry–Pérot interferometer, which enabled the detection of curvature with a root-mean-square error (RMSE) of 0.0034 L mm -1( R2=1), axial pressure with an RMSE of 0.0564 bar ( R2=0.99), and temperature with an RMSE of 0.0265 °C ( R2=1). At the time of writing, there is no commercially available instrument that can perform these measurements simultaneously.en2194-877120242147155Copernicus Publicationshttps://creativecommons.org/licenses/by/4.0/MLE@TUHHTechnology::621: Applied Physics::621.3: Electrical Engineering, Electronic EngineeringTechnology::620: EngineeringNatural Sciences and Mathematics::530: PhysicsJournal Article2024-07-0910.15480/882.1312910.5194/jsss-13-147-202410.15480/882.13129Journal Article