Surface plasmon enhanced fast electron emission from metallised fibre optic nanotips
Surface plasmon enhanced fast electron emission from metallised fibre optic nanotips
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DOI：
10.1088/1367-2630/aba85b
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发表时间：
2020-08-01
影响因子：
3.3
通讯作者：
Batelaan，Herman
中科院分区：
文献类型：
--
作者：
Keramati，Sam;Passian，Ali;Batelaan，Herman
光纤纳米尖端的电子发射的物理机制，即隧道效应、多光子和电子发射，要么阻止快速开关，要么需要强激光场。时间分辨的电子发射纳米尺寸的来源发现的应用范围从材料特性的量子相干的基础研究。我们提出了一种纳米尺寸的电子源，能够快速开关（100 ns），可以驱动低功率飞秒激光。在低功率激光下，其发光的物理机制是表面等离子体增强的阈上光电发射。观察到电子发射峰，并为共振等离子体激元激发提供支持。电子源是一根金属涂层的光纤，它逐渐变细成纳米大小的尖端。光纤是柔性的，并且背面发光，便于定位。该源的工作原理是每个激光脉冲只有几个nJ，这使得它成为一个多功能的发射器，可以用于纳米测量、多分辨率电子光刻和扫描探针显微镜。
Physical mechanisms of electron emission from fibre optic nanotips, namely, tunnelling, multi-photon, and thermionic emission, either prevent fast switching or require intense laser fields. Time-resolved electron emission from nano-sized sources finds applications ranging from material characterisation to fundamental studies of quantum coherence. We present a nano-sized electron source capable of fast-switching (⩽ 1 ns) that can be driven with low-power femtosecond lasers. The physical mechanism that can explain emission at low laser power is surface plasmon enhanced above-threshold photoemission. An electron emission peak is observed and provides support for resonant plasmonic excitation. The electron source is a metal-coated optical fibre tapered into a nano-sized tip. The fibre is flexible and back illuminated facilitating ease of positioning. The source operates with a few nJ per laser pulse, making this a versatile emitter that enables nanometrology, multisource electron-lithography and scanning probe microscopy.