Optical parametric amplification by monolayer transition metal dichalcogenides
Optical parametric amplification by monolayer transition metal dichalcogenides
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DOI：
10.1038/s41566-020-00728-0
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发表时间：
2020-12-21
期刊：
影响因子：
35
通讯作者：
Cerullo, Giulio
中科院分区：
文献类型：
--
作者：
Trovatello, Chiara;Marini, Andrea;Cerullo, Giulio
光参量放大是一种二阶非线性过程，通过产生空闲场，光信号被泵浦放大。这种机制本质上与自发的参数下转换有关，它目前构成了纠缠光子对产生的基础(2)，这是现代量子技术中利用的一个过程。在这里，我们演示了在极限厚度下的单程光学参量放大；使用半导体过渡金属二卤代化合物(3，4)，我们证明了通过单原子层的超传播可以实现放大。这种二维极限的二阶非线性相互作用绕过了相位匹配要求(5)，实现了超宽带放大带宽。与第一性原理计算一致，我们观察到放大过程与信号场和泵浦光场的面内极化无关。通过AA堆积多层膜的使用，我们为转换效率的扩展提供了一条清晰的途径。我们的结果为开发原子大小的可调谐辐射源铺平了道路，该辐射源在纳米光子学和量子信息技术中具有潜在的应用前景。
Optical parametric amplification is a second-order nonlinear process whereby an optical signal is amplified by a pump via the generation of an idler field'. This mechanism is inherently related to spontaneous parametric down-conversion, which currently constitutes the building block for entangled photon pair generations(2), a process that is exploited in modern quantum technologies. Here we demonstrate single-pass optical parametric amplification at the ultimate thickness limit; using semiconducting transition metal dichalcogenides(3,4), we show that amplification can be attained over propagation through a single atomic layer. Such a second-order nonlinear interaction at the two-dimensional limit bypasses phase-matching requirements(5) and achieves ultrabroad amplification bandwidths. In agreement with first-principle calculations, we observe that the amplification process is independent of the in-plane polarization of signal and pump fields. By the use of AA-stacked multilayers, we present a clear pathway towards the scaling of conversion efficiency. Our results pave the way for the development of atom-sized tunable sources of radiation with potential applications in nanophotonics and quantum information technology.