为了提升光纤拉曼检测系统的响应速度，提出一种基于结构牢固、易于气体扩散的开放式微结构光纤的气体拉曼检测系统。为了深入研究拉曼信号与微结构光纤结构参数的依赖关系，推导出基于前向/后向拉曼耦合的拉曼信号公式，并根据此公式完成对气体光纤拉曼检测系统的结构优化。通过优化光纤结构实现了增强系统灵敏度特性的目的。分析结果表明，拉曼信号强度与光纤结构之间存在一最佳值，最佳值(纤芯、悬臂厚度)取决于基底材料折射率、纤芯直径和悬臂厚度等具体的光纤结构参数。二氧化硅材料光纤的拉曼信号较强区域条件是纤芯厚度为120~150 nm。

For quickening the gas sensing speed of fiber Raman detection system, a fiber Raman analyzer with sideopened configuration is proposed and explored. For exploring the relationship between Raman intensity and fiber parameters, a Raman sensing model is introduced for optimizing effective mode area and enhancing normalized intensity overlap between Raman sensing light and analyte. Calculations predict that there is a trade-off between Raman intensity and fiber parameters, while the optimal trade-off dependes on the refractive index of the background material, core diameter and strut′s thickness. The optimized fiber core size for silica-based fiber Raman analyzer is 120~150 nm.