Qin Yanyan, Huang Ruidong, Lu Fengya, Tang Haibin, Yao Bo, Mao Qinghe
Opt Express. 2022 Oct 10;30(21):37507-37518. doi: 10.1364/OE.471597.
In this paper, we investigate the effects of taper angle on the SERS detection sensitivity using tapered fiber probes with single-layer uniform gold spherical nanoparticles (GSNs). We show that the photothermal damage caused by excessive excitation laser power is the main factor that restricts the improvement of detection sensitivity of tapered fiber probes. Only when the cone angle is appropriate can a balance be achieved between increasing the excitation laser power and suppression of the transmission and scattering losses of the nanoparticles on the tapered fiber surface, thereby obtaining the best SERS detection sensitivity. Furthermore, the optimal cone angle depends on the complex refractive index of the equivalent composite dielectric (ECD) layer containing GSNs. For three SERS fiber probes with different ECD layers, the optimal cone angles measured are between 11-13°.
在本文中，我们使用带有单层均匀金纳米球（GSNs）的锥形光纤探头研究了锥角对表面增强拉曼散射（SERS）检测灵敏度的影响。我们表明，过高的激发激光功率所引起的光热损伤是限制锥形光纤探头检测灵敏度提高的主要因素。只有当锥角适当时，才能在增加激发激光功率与抑制锥形光纤表面纳米颗粒的传输和散射损耗之间实现平衡，从而获得最佳的SERS检测灵敏度。此外，最佳锥角取决于包含GSNs的等效复合电介质（ECD）层的复折射率。对于具有不同ECD层的三种SERS光纤探头，测得的最佳锥角在11°至13°之间。
