aBeam Technologies, Hayward, CA, 94541, USA.
The Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA, 94720, USA.
Sci Rep. 2017 May 10;7(1):1651. doi: 10.1038/s41598-017-01871-5.
One of the major challenges to the widespread adoption of plasmonic and nano-optical devices in real-life applications is the difficulty to mass-fabricate nano-optical antennas in parallel and reproducible fashion, and the capability to precisely place nanoantennas into devices with nanometer-scale precision. In this study, we present a solution to this challenge using the state-of-the-art ultraviolet nanoimprint lithography (UV-NIL) to fabricate functional optical transformers onto the core of an optical fiber in a single step, mimicking the 'campanile' near-field probes. Imprinted probes were fabricated using a custom-built imprinter tool with co-axial alignment capability with sub <100 nm position accuracy, followed by a metallization step. Scanning electron micrographs confirm high imprint fidelity and precision with a thin residual layer to facilitate efficient optical coupling between the fiber and the imprinted optical transformer. The imprinted optical transformer probe was used in an actual NSOM measurement performing hyperspectral photoluminescence mapping of standard fluorescent beads. The calibration scans confirmed that imprinted probes enable sub-diffraction limited imaging with a spatial resolution consistent with the gap size. This novel nano-fabrication approach promises a low-cost, high-throughput, and reproducible manufacturing of advanced nano-optical devices.
在将等离子体和纳米光学器件广泛应用于实际应用中，面临的主要挑战之一是难以以平行和可重复的方式大规模制造纳米光学天线，并且难以以纳米级精度将纳米天线精确地放置到器件中。在这项研究中，我们使用最先进的紫外纳米压印光刻（UV-NIL）技术来解决这一挑战，该技术可在单个步骤中将功能光学变压器制作到光纤的核心上，模拟“钟塔”近场探针。使用具有同轴对准功能的定制压印工具以及亚 <100nm 位置精度制造了压印探针，然后进行金属化步骤。扫描电子显微镜照片证实了高保真度和高精度，具有较薄的残留层，可促进光纤和压印光学变压器之间的高效光学耦合。在实际的 NSOM 测量中，使用压印的光学变压器探针执行标准荧光珠的高光谱荧光映射。校准扫描证实，压印探针可实现亚衍射极限成像，其空间分辨率与间隙尺寸一致。这种新颖的纳米制造方法有望实现低成本、高通量和可重复制造的先进纳米光学器件。
