Cui Tao, Shen Yan, Cheng Ao, Zhan Runze, Zheng Zebo, Tian Bo, Shi Jia, Ke Yanlin, Shao Lei, Chen Huanjun, Deng Shaozhi
State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou 510275, China.
Nanophotonics. 2023 Oct 25;12(22):4185-4193. doi: 10.1515/nanoph-2023-0480. eCollection 2023 Nov.
Plasmonic waveguides have attracted tremendous interest due to efficiently confining photons on the subwavelength spatial scale to be beating the propagation diffraction limit. Transition metal molybdenum (Mo) exhibits outstanding properties in light trapping and electromagnetic field confining, making it potentially valuable in 1.55 μm plasmonic waveguide applications. However, the reliable fabrication of high-quality Mo plasmonic waveguides is a significant challenge. A real-space micro-imaging study of the surface plasmon on Mo structures is still absent. In this study, we successfully prepared a single-crystalline Mo microrod waveguide structure and fabricated subwavelength gratings on it. The diffraction gratings were designed, optimized, and etched to excite the surface plasmon polariton behaviour of Mo for the first time. The grating-optimized Mo microrod single-crystal reveals highly efficient waveguide performance around near-infrared spectroscopy, exhibiting a long propagation length of 32 μm and a low transmission loss of 0.067 dB μm. The results provide an alternative to advanced materials research and optical device applications of plasmonic waveguide systems.
等离子体波导因其能在亚波长空间尺度上高效限制光子从而突破传播衍射极限而备受关注。过渡金属钼（Mo）在光捕获和电磁场限制方面表现出优异性能，使其在1.55μm等离子体波导应用中具有潜在价值。然而，高质量钼等离子体波导的可靠制备是一项重大挑战。目前仍缺乏对钼结构表面等离子体的实空间微观成像研究。在本研究中，我们成功制备了单晶钼微棒波导结构并在其上制作了亚波长光栅。首次设计、优化并蚀刻了衍射光栅以激发钼的表面等离子体激元行为。经光栅优化的钼微棒单晶在近红外光谱范围内展现出高效的波导性能，传播长度达32μm，传输损耗低至0.067dB/μm。这些结果为等离子体波导系统的先进材料研究和光学器件应用提供了一种替代方案。
