当前位置: X-MOL 学术J. Spectrosc. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Optical Feedback for Sensitivity Enhancement in Direct Raman Detection of Liquids
Journal of Spectroscopy ( IF 2 ) Pub Date : 2021-05-10 , DOI: 10.1155/2021/5588417
Miao Liu 1 , Yunyun Mu 1 , Jingyun Hu 1 , Jiajun Li 1 , Xinping Zhang 1
Affiliation  

Detection of low-concentration molecules in liquids has been a challenge in sensing technologies. Raman spectroscopy is an effective approach for trace detection, which is in fact a “volume-excitation” and “volume-collection” technique in the analysis of liquid samples. However, for the commonly employed one-pass excitation and back-scattering detection scheme, a large portion of both the excitation laser energy and the Raman-scattering light energy is wasted without efficient reuse or collection. In this consideration, we demonstrate a broadband optical feedback scheme by a curved high-reflection mirror for both the excitation and the Raman-scattering light, so that the excitation and the forward-propagating Raman signal can be back-reflected and collected with a high efficiency. Using the “F+2f” design, where F and f are the focal lengths of the focusing lens and curved reflection mirror, respectively, we were able to not only produce two focuses of the excitation laser beam but also extend the Raman interaction by a doubled distance. For the detection of pure ethanol molecules and the R6G molecules in water with a concentration of 10−3 M, the Raman signal was enhanced by a factor of about 5.6. The optical feedback scheme and discovered optical mechanisms supply effective improvements to the Raman spectroscopic measurements on liquid samples.

中文翻译:

光学反馈可提高液体直接拉曼检测的灵敏度

液体中低浓度分子的检测一直是传感技术的挑战。拉曼光谱法是痕量检测的有效方法,实际上是液体样品分析中的“体积激发”和“体积收集”技术。然而,对于通常采用的单程激发和反向散射检测方案,在没有有效的再利用或收集的情况下,浪费了激发激光能量和拉曼散射光能量的大部分。考虑到这一点,我们演示了通过弯曲的高反射镜对激发光和拉曼散射光进行宽带光反馈的方案,因此,激发光和前向传播的拉曼信号可以向后反射并以较高的反射率收集。效率。使用“ F + 2f”设计,其中Fff分别是聚焦透镜和曲面反射镜的焦距,我们不仅能够产生激发激光束的两个焦点,而且能够将拉曼相互作用扩大一倍。为了检测浓度为10 -3  M的水中的纯乙醇分子和R6G分子,拉曼信号增强了约5.6倍。光学反馈方案和发现的光学机制为液体样品的拉曼光谱测量提供了有效的改进。
更新日期:2021-05-10
down
wechat
bug