Among all the nonlinear effects stimulated Brillouin scattering offers the highest gain in solid materials and has demonstrated advanced photonics functionalities in waveguides. The large compressibility of gases suggests that stimulated Brillouin scattering may gain in efficiency with respect to condensed materials. Here, by using a gas-filled hollow-core fibre at high pressure, we achieve a strong Brillouin amplification per unit length, exceeding by six times the gain observed in fibres with a solid silica core. This large amplification benefits from a higher molecular density and a lower acoustic attenuation at higher pressure, combined with a tight light confinement. Using this approach, we demonstrate the capability to perform large optical amplifications in hollow-core waveguides. The implementations of a low-threshold gas Brillouin fibre laser and a high-performance distributed temperature sensor, intrinsically free of strain cross-sensitivity, illustrate the potential for hollow-core fibres, paving the way to their integration into lasing, sensing and signal processing.

在所有非线性效应中，受激布里渊散射在固体材料中提供了最高的增益，并展示了波导中先进的光子学功能。气体的大可压缩性表明，受激布里渊散射对冷凝材料的效率可能提高。在这里，通过在高压下使用充气的中空纤维，我们在单位长度上实现了强大的布里渊放大率，是具有实心二氧化硅芯的纤维所获得的增益的六倍。这种较大的放大得益于较高的分子密度和较高压力下的较低声衰减，以及严格的光限制。使用这种方法，我们演示了在空心波导中执行大型光学放大的能力。