Terahertz saturable absorbers from liquid phase exfoliation of graphite.
Terahertz saturable absorbers from liquid phase exfoliation of graphite.
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DOI：
10.1038/ncomms15763
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发表时间：
2017-06-15
影响因子：
16.6
通讯作者：
Vitiello MS
中科院分区：
文献类型：
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作者：
Bianchi V;Carey T;Viti L;Li L;Linfield EH;Davies AG;Tredicucci A;Yoon D;Karagiannidis PG;Lombardi L;Tomarchio F;Ferrari AC;Torrisi F;Vitiello MS
工作在太赫兹（THz）频率的可饱和吸收体（SA）可以为被动锁模THz微源的发展开辟新的前沿。在这里，我们报告的太赫兹SA的转移涂层和喷墨印刷的单层和少层石墨烯薄膜制备的液相剥离石墨。用3.5 THz量子级联激光器进行的开孔z扫描测量显示，透明度调制为80%，几乎比迄今报道的THz频率大一个数量级。傅里叶变换红外光谱提供了带内控制吸收漂白的证据。这些结果为石墨烯基SA与电泵浦THz半导体微源的集成铺平了道路，具有在短时间尺度上激发特定跃迁至关重要的应用前景，例如飞行时间断层扫描，量子系统的相干操纵，气体，复杂分子和冷样品的时间分辨光谱以及超高速通信，提供前所未有的紧凑性和分辨率。石墨烯显示出可饱和吸收的前景，这是超快激光的一个关键特性，但在太赫兹区域工作的石墨烯可饱和吸收体受到低吸收调制的影响。在这里，作者报告了基于喷墨打印石墨烯的太赫兹可饱和吸收体，具有80%的透明度调制。
Saturable absorbers (SA) operating at terahertz (THz) frequencies can open new frontiers in the development of passively mode-locked THz micro-sources. Here we report the fabrication of THz SAs by transfer coating and inkjet printing single and few-layer graphene films prepared by liquid phase exfoliation of graphite. Open-aperture z-scan measurements with a 3.5 THz quantum cascade laser show a transparency modulation ∼80%, almost one order of magnitude larger than that reported to date at THz frequencies. Fourier-transform infrared spectroscopy provides evidence of intraband-controlled absorption bleaching. These results pave the way to the integration of graphene-based SA with electrically pumped THz semiconductor micro-sources, with prospects for applications where excitation of specific transitions on short time scales is essential, such as time-of-flight tomography, coherent manipulation of quantum systems, time-resolved spectroscopy of gases, complex molecules and cold samples and ultra-high speed communications, providing unprecedented compactness and resolution. Graphene shows promise for saturable absorption, a key property for ultrafast lasing, yet graphene saturable absorbers operating in the terahertz region suffer from low absorption modulation. Here, the authors report terahertz saturable absorbers based on inkjet printed graphene with 80% transparency modulation.