A fiber-optic sensing scheme for the simultaneous measurement of strain and a wide range of temperatures has been investigated by combining the properties of the fiber Bragg grating (FBG) and the fluorescence from a rare-earth-doped photosensitive fiber. The temperature-dependent fluorescence peak power ratio of the two peaks occurring around 1535 nm and 1552 nm from the amplified spontaneous emission due to the [sup 4]I[sub 13/2]↔[sup 4]I[sub 15/2] transitions in Er[sup 3+]-doped tin–germanosilicate fiber, with 980 nm pumping, and the dual functionality of the FBG were exploited in this scheme. The sensor is based on a single FBG written in a small length (∼10 cm) of the above fiber, which can be used for the simultaneous measurement of strain and temperature over ranges of 0–1150 μ[variant_greek_epsilon] and 22–500 °C, with root-mean-square errors of 36 μ[variant_greek_epsilon] and 6 °C, respectively