Processing a graphene surface by irradiation with a fs-pulsed laser at energies below the ablation threshold allows the production of non-thermally modified regions with slightly different properties than pristine graphene. Oxidized nanoislands, optical forging, and nanopore networks are modifications of the graphene structure recently reported using a wide range of fs-laser energies. In this work, we first determined the pulse energy threshold of a fs-laser for the ablation of a commercial CVD graphene sample. Then we irradiated the sample in an extended range of pulse energies relative to the ablation threshold value. The irradiation process was simultaneously monitored by Raman spectroscopy, and the evolution of each Raman parameter (central position, bandwidth, and intensity) was analyzed. Special attention was given to the pulse energy that produced linear relationships between most Raman parameter pairs. These linear correlations evidence the interrelation between multiple Raman parameters and a soft processing method applicable to the controlled modification of the graphene lattice.

中文翻译：

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飞秒激光辐照石墨烯软改性的拉曼研究

通过用飞秒脉冲激光以低于烧蚀阈值的能量照射来处理石墨烯表面，可以产生与原始石墨烯性质略有不同的非热改性区域。氧化纳米岛、光学锻造和纳米孔网络是最近报道的使用各种飞秒激光能量对石墨烯结构的修饰。在这项工作中，我们首先确定了飞秒激光烧蚀商用 CVD 石墨烯样品的脉冲能量阈值。然后，我们以相对于烧蚀阈值的扩展脉冲能量范围照射样品。通过拉曼光谱同时监测照射过程，并分析每个拉曼参数（中心位置、带宽和强度）的演变。特别关注在大多数拉曼参数对之间产生线性关系的脉冲能量。这些线性相关性证明了多个拉曼参数与适用于石墨烯晶格受控修饰的软加工方法之间的相互关系。