论文标题
金属硝酸钛的高谐波一代
High-harmonic generation in metallic titanium nitride
论文作者
论文摘要
高谐波一代是非线性光学元件的基石。它已在各种晶体系统中进行了证明，包括电介质，半导体和半金属以及气体，由于其低损伤阈值而排出了金属。在这里，我们报告了金属硝化钛（TIN）膜中的高谐波一代。 TIN是一种难治性等离子金属，以其高融化温度和激光损伤阈值而闻名，其光学特性与黄金相似。我们表明，锡可以承受高峰强度高达13 tw/cm $^2 $的激光脉冲，比黄金高1个数量级，从而使内和谐波的发射达到11 eV的光子能量。这些谐波可以为产生真空紫外线（VUV）频率梳子的紧凑，有效的等离子设备铺平道路。通过数值计算和实验研究，我们表明发射的VUV辐射的强度缩放和角各向异性来自TIN的各向异性传导带的结构，从而证实了其内的原始起源。
High-harmonic generation is the cornerstone of nonlinear optics. It has been demonstrated in a wide range of crystalline systems including dielectrics, semiconductors, and semi-metals, as well as in gases, leaving metals out due to their low damage threshold. Here, we report on the high-harmonic generation in metallic titanium nitride (TiN) films. TiN is a refractory plasmonic metal, known for its high melting temperature and laser damage threshold, with optical properties similar to those of gold. We show that TiN can withstand laser pulses with peak intensities as high as 13 TW/cm$^2$, one order of magnitude higher than gold, enabling the emission of intraband harmonics up to photon energies of 11 eV. These harmonics can pave the way for compact and efficient plasmonic devices producing vacuum ultraviolet (VUV) frequency combs. Through numerical calculations and experimental studies, we show that the intensity scaling and angular anisotropy of the emitted VUV radiation stem from the anisotropic conduction band structure of TiN, thus confirming its intraband origin.
