Single molecule absorption spectroscopy using nanophotonic devices for non-fluorescent molecules

本研究的目的是发展灵敏的单分子吸收光谱的非荧光分子的分子吸收截面显着增加与纳米光子器件。该项目的主要成果有以下三点。(1)我们证明了单个胶体量子点可以与光场耦合，耦合效率为7.4%。该耦合效率估计为0.1%的光吸收，即使在室温下的光学晶体上的单分子。(2)我们使用数值模拟研究了光学纳米纤维与各种纳米光子结构的耦合，并找到了最佳可能的纳米光子波导结构，其中可以获得单分子的最大吸收。(3)我们已经证明了这种吸收光谱的独立氮化硅波导的制造。

This research aims at development of sensitive single molecule absorption spectroscopy of non-fluorescent molecules by increasing molecular absorption cross-section dramatically with nanophotonic devices. The main results of this project were following three. (1) We demonstrated that single colloidal quantum dots can couple with optical nanofiber with a coupling efficiency of 7.4%. This coupling efficiency estimates 0.1% of optical absorption by single molecules on optical nanofiber even at room temperature. (2) We investigated the coupling of the optical nanofibers with various nanophotonic structures using numerical simulations and found best possible nanophotonic waveguide structures where the maximum absorption of single molecules can be obtained. (3) We have demonstrated the fabrication of free-standing silicon nitride waveguides for this absorption spectroscopy.