Huang Xiaohui, Qi Yun, Pang Meng, Yang Fan
Opt Lett. 2025 Mar 1;50(5):1536-1539. doi: 10.1364/OL.549654.
Stimulated Brillouin scattering (SBS) in gas-filled hollow-core fibers (HCFs) provides high gain and narrow linewidth, making it a promising platform for advanced photonic applications. While Brillouin gain is known to depend quadratically on pressure and linewidth inversely on pressure, the combined effect of pressure and temperature - through their influence on gas density-has not been fully explored. In this study, we demonstrate that lowering the gas temperature from 373.15 K to 233.15 K at a pressure of 100 bars (using nitrogen) leads to a six-fold increase in Brillouin gain and a twofold reduction in linewidth. We systematically investigate the temperature dependence of key Brillouin parameters, including gain, frequency shift, linewidth, acoustic velocity, and temperature sensitivity, in nitrogen and carbon dioxide gases. The results reveal distinct temperature-dependent behaviors, aligning well with theoretical predictions, and provide new insights, to the best of our knowledge, into optimizing SBS performance in gas-filled hollow-core fibers.
充气空心光纤（HCF）中的受激布里渊散射（SBS）具有高增益和窄线宽，使其成为先进光子应用的一个有前景的平台。虽然已知布里渊增益与压力成二次方关系，线宽与压力成反比，但压力和温度通过对气体密度的影响所产生的综合效应尚未得到充分研究。在本研究中，我们证明在100巴的压力下（使用氮气）将气体温度从373.15 K降低到233.15 K会导致布里渊增益增加六倍，线宽减小两倍。我们系统地研究了氮气和二氧化碳气体中关键布里渊参数的温度依赖性，包括增益、频移、线宽、声速和温度灵敏度。结果揭示了明显的温度依赖行为，与理论预测吻合良好，并据我们所知为优化充气空心光纤中的SBS性能提供了新的见解。
