Singlemode-multimode-singlemode fiber structures (SMS) based on distinct sections of a pure silica multimode fiber (coreless-MMF) with diameters of 125 and 55 μm, were reported for the measurement of curvature and temperature. The sensing concept relies on the multimode interference that occurs in the coreless-MMF section and, in accordance with the length of the MMF section used, two fiber devices were developed: one based on a bandpass filter (self-image effect) and the other on a band-rejection filter. Maximum sensitivities of 64.7 nṁm and 13.08 pm° C could be attained, for curvature and temperature, respectively, using the band-rejection filter with 55 μ m-MMF diameter. A proof of concept was also explored for the simultaneous measurement of curvature and temperature by means of the matrix method. © 2012 IEEE.302335693575Soldano, L.B., Pennings, E.C.M., Optical multi-mode interference devices based on self-imaging: Principles and applications (1995) J. Lightw. Technol, 13, pp. 615-627Frazão, O., Silva, S., Viegas, J., Ferreira, L.A., Araújo, F.M., Santos, J.L., Optical fiber refractometry based on multimode interference (2011) Appl. Opt, 50, pp. E184-188Mohammed, W.S., Smith, P.W.E., Gu, X., All-fiber multimode interference bandpass filter (2006) Optics Letters, 31 (17), pp. 2547-2549. , DOI 10.1364/OL.31.002547Biazoli, C.R., Silva, S., Franco, M.A.R., Frazão, O., Cordeiro, C.M.B., Multimode interference tapered fiber refractive index sensors Appl. Opt., , submittedCastillo-Guzman, A., Antonio-Lopez, J.E., Selvas-Aguilar, R., May-Arrioja, D.A., Estudillo-Ayala, J., Wa, P.L., Widely tunable erbium-doped fiber laser based on multimode interference effect (2010) Opt. Exp, 18, pp. 591-597Li, E., Sensitivity-enhanced fiber-optic strain sensor based on interference of higher order modes in circular fibers (2007) IEEE Photon. Technol. Lett, 19, pp. 1266-1268Gao, R.X., Wang, Q., Zhao, F., Meng, B., Qu, S.L., Optimal design and fabrication of SMS fiber temperature sensor for liquid (2010) Opt. Commun, 283, pp. 3149-3152Gong, Y., Zhao, T., Rao, Y., Wu, Y., All-fiber curvature sensor based on multimode interference (2011) IEEE Photon. Technol. Lett, 23, pp. 679-681Silva, S., Pachon, E.G.P., Franco, M.A.R., Hayashi, J.G., Malcata, F.X., Frazão, O., Jorge, P., Cordeiro, C.M.B., Ultra-high temperaturesensitivity sensor based on multimode interference (2012) Appl. Opt, 51, pp. 3236-3242Wu, Q., Semenova, Y., Hatta, A.M., Wang, P., Farrell, G., Singlemode-multimode-singlemode fiber structures for simultaneous measurement of strain and temperature (2011) Microw. Opt. Technol. Lett, 53, pp. 2181-2185Coelho, L., Kobelke, J., Schuster, K., Frazão, O., Multimode interference in outer cladding large-core air-clad photonic crystal fiber (2012) Microw. Opt. Technol. Lett, 54, pp. 1009-1011Silva, S., Frazão, O., Viegas, J., Ferreira, L.A., Araújo, F.M., Malcata, F.X., Santos, J.L., Temperature and strain-independent curvature sensor based on a singlemode/multimode fiber optic structure (2011) Meas. Sci. Technol, 22, p. 085201Jin, W., Michie, W.C., Thursby, G., Konstantaki, M., Culshaw, B., Simultaneous measurement of strain and temperature: Error analysis (1997) Optical Engineering, 36 (2), pp. 598-609Okamoto, K., (2006) Fundamentals of Optical Waveguides, , NewYork: ElsevierKawano, K., Kitoh, T., (2001) Introduction to Optical Waveguide Analysis, pp. 165-230. , New York: Wiley ch. 5