On the determination of χ((2)) in thin films: a comparison of one-beam second-harmonic generation measurement methodologies.
On the determination of χ((2)) in thin films: a comparison of one-beam second-harmonic generation measurement methodologies.
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DOI：
10.1038/srep44581
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发表时间：
2017-03-20
影响因子：
4.6
通讯作者：
Baets R
中科院分区：
文献类型：
--
作者：
Hermans A;Kieninger C;Koskinen K;Wickberg A;Solano E;Dendooven J;Kauranen M;Clemmen S;Wegener M;Koos C;Baets R
薄膜样品的二阶极化率（χ（2））的确定可能是一个微妙的问题，因为成熟的χ（2）测量方法（例如Maker条纹技术）最适合于具有通常从几十微米到几毫米的大厚度的非线性材料。在这里，我们比较了两种不同的二次谐波产生装置和相应的测量方法，这对薄膜χ（2）表征特别有利。这项工作允许交叉检查从相同样本中获得的χ（2），并确定各种技术的主要误差来源。光子集成电路的发展使得非线性薄膜特别令人感兴趣，因为它们可以被加工成长波导以创建有效的非线性器件。所研究的样品是ABC型纳米层压材料，这是最近由两个不同的研究小组报道的。然而，随后的分析可以是有用的，所有的研究人员活跃在该领域的薄膜χ（2）表征。
The determination of the second-order susceptibility (χ(2)) of thin film samples can be a delicate matter since well-established χ(2) measurement methodologies such as the Maker fringe technique are best suited for nonlinear materials with large thicknesses typically ranging from tens of microns to several millimeters. Here we compare two different second-harmonic generation setups and the corresponding measurement methodologies that are especially advantageous for thin film χ(2) characterization. This exercise allows for cross-checking the χ(2) obtained for identical samples and identifying the main sources of error for the respective techniques. The development of photonic integrated circuits makes nonlinear thin films of particular interest, since they can be processed into long waveguides to create efficient nonlinear devices. The investigated samples are ABC-type nanolaminates, which were reported recently by two different research groups. However, the subsequent analysis can be useful for all researchers active in the field of thin film χ(2) characterization.