Nanostructure patterning on optical fibers enables miniaturized optrodes for photonic and plasmonic applications. Here we report a direct nanoimprint technique to produce high-quality nanostructure arrays on optical fiber endfaces. It has only one single step: imprinting optical fiber tips against a mold with nanostructures at the elevated temperature. This new method abandons resist used in traditional fiber-imprinting methods. Hundreds of fibers can be shaped simultaneously with one mold within minutes. The imprinted nanostructure arrays on optical fibers are transformed into plasmonic optrodes through metal deposition. Variation of imprint depths and mold patterns allows tailoring of the plasmonic resonances of these nanostructure arrays for high-performance refractometric sensing and on-fiber polarization. The sensitivity of 690 nm/RIU and figure of merit of 50 are both among the highest values for similar plasmonic nanostructure arrays. This resist-free nanoimprint paves the way towards a low-cost and high-throughput realization of plasmonic optrodes and their wide applications.

光纤上的纳米结构图案可实现用于光子和等离子体应用的小型化电极。在这里，我们报告了一种直接的纳米压印技术，可以在光纤端面上生产高质量的纳米结构阵列。它只有一个步骤：在高温下将光纤头压印在具有纳米结构的模具上。这种新方法放弃了传统纤维压印方法中使用的抗蚀剂。数以百计的纤维可以在几分钟内用一个模具同时成型。通过金属沉积将光纤上的纳米结构压印阵列转变成等离子激元。压印深度和模具图案的变化允许定制这些纳米结构阵列的等离子体共振，以实现高性能的折射检测和光纤偏振。690 nm / RIU的灵敏度和50的品质因数，都是类似等离子纳米结构阵列的最高值。这种无抗蚀剂的纳米压印为等离子电极及其低成本应用铺平了道路。