Discriminative strain and temperature measurement using Brillouin scattering and fluorescence in erbium-doped optical fiber.

We develop a novel discriminative sensing technique of strain and temperature using Brillouin scattering and fluorescence in an erbium-doped fiber (EDF). First, we show that the fluorescence intensity ratio (FIR), the ratio of the fluorescence intensities at two different wavelengths (1530 nm and 1565 nm in this experiment), is linearly dependent on temperature (with a coefficient of 5.6 × 10⁻⁴ /°C) but almost independent of strain. Then, by combined use of the FIR and the Brillouin frequency shift in an EDF, we experimentally demonstrate discriminative measurements of strain and temperature with four different sets of strain and temperature changes.