Absolute temperature sensing in the 67-350K range using Brillouin scattering in gases

This paper proposes a novel temperature sensing method using stimulated Brillouin scattering in a hollow-core fiber filled with gas. Compared to classical Brillouin sensors, the Brillouin response of gases shows a higher sensitivity at cryogenic temperatures and a null sensitivity to strain. Experimental results demonstrate that argon is highly efficient for ambient temperature sensing, providing a 2.4-fold gain coefficient compared to silica fibers. Meanwhile, neon proves ideal for cryogenic sensing, offering a potential gain coefficient at 77 K that is twice that of silica fibers at ambient temperature.