Antenna-enhanced high harmonic generation in a wide-bandgap semiconductor ZnO
Antenna-enhanced high harmonic generation in a wide-bandgap semiconductor ZnO
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宽带隙半导体 ZnO 中天线增强高次谐波的产生
DOI：
10.1051/epjconf/201920502024
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
and S. Ashihara
中科院分区：
文献类型：
--
作者：
K. Imasaka;T. Kaji;T. Shimura;and S. Ashihara
固体中的高次谐波在相干极紫外光源、全光学能带结构重建和电子动力学计量等方面具有巨大的应用潜力。由等离子体近场驱动的固体HHG将开辟一个新的范例，利用紧凑的激光器实现高重复率HHG，利用超表面进行HHG操纵，并精确控制载体轨迹。在本文中，我们证明了天线增强HHG在宽带隙半导体ZnO。利用金纳米天线在2 μm波长处的共振，我们成功地在约0.02 TW/cm^2的输入强度下触发了高次谐波，并观察到了高达9阶的谐波辐射。在热点处的数量级增强的转换效率带来总产量的十倍增强。光谱选择规则反映了晶体的对称性，表明纳米尺度的EUV光源和能带结构重建的可能性。
High harmonic generation (HHG) in solids has great potential for coherent extreme ultraviolet (EUV) sources, all-optical band-structure reconstruction, and electron dynamics metrology. Solid HHG driven by plasmonic near-fields will open a new paradigm, enabling high repetition-rate HHG with a compact laser, HHG manipulation with meta-surfaces, and precise control over carrier trajectory. In this paper, we demonstrate antenna-enhanced HHG in a wide-bandgap semiconductor ZnO. By exploiting gold nano-antennas resonating at the driver wavelength of 2 μm, we successfully trigger HHG at input intensity of ~0.02 TW/cm^2 and observe harmonic radiations up to 9th-order. Orders-of-magnitude enhanced conversion efficiency at the hot-spots brings about ten-fold enhancement in the total yield. The spectral selection rule is found to reflect crystal symmetry, suggesting the possibility of nano-scaled EUV sources and band-structure reconstruction.