Yang Fan, Gyger Flavien, Thévenaz Luc
Ecole Polytechnique Fédérale de Lausanne (EPFL), Group for Fibre Optics, Lausanne, Switzerland.
Nat Photonics. 2020 Nov;14(11):700-708. doi: 10.1038/s41566-020-0676-z. Epub 2020 Aug 10.
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具有最高的增益，并已在波导中展现出先进的光子学功能。气体的高可压缩性表明，受激布里渊散射相对于凝聚态材料可能具有更高的效率。在此，我们通过使用高压充气空心光纤，实现了每单位长度的强布里渊放大，比实心二氧化硅芯光纤中观察到的增益高出六倍。这种大放大率得益于更高的分子密度、更高压力下更低的声衰减以及紧密的光限制。利用这种方法，我们展示了在空心波导中进行大光学放大的能力。低阈值气体布里渊光纤激光器和本质上无应变交叉敏感性的高性能分布式温度传感器的实现，说明了空心光纤的潜力，为其集成到激光、传感和信号处理中铺平了道路。
