Institute of Physics, State Academy of Sciences, Unjong District, Pyongyang, Democratic People's Republic of Korea.
Phys Chem Chem Phys. 2019 Dec 11;21(48):26615-26620. doi: 10.1039/c9cp05186d.
The efficient generation of a broadband frequency comb from the visible to ultraviolet region is a challenging task despite its importance for nanoscale spectroscopy and sensing applications. In this paper, we reported broadband visible-near infrared and deep ultraviolet generation by four-wave mixing and high-order stimulated Raman scattering from hybrid metasurfaces made of plasmonic nanoantennae embedded with Raman-active diamond nanoparticles as examples. Upon two-color near-infrared pumping tuned to a Raman resonance, one can generate a visible-near infrared frequency comb with a major contribution of high-order stimulated Raman scattering by the coherent modulation of the Raman medium and simultaneously, a broad deep ultraviolet frequency comb is radiated by four-wave mixing and third-harmonic generations. The efficiencies of the individual spectral peaks reached values in the order of 10-8-10-2% under pumping with pulses with a peak intensity of about 33 GW cm-2 and a duration of 100 fs in the near infrared region.
尽管在纳米光谱学和传感应用中具有重要意义，但从可见光到紫外区域高效产生宽带频率梳仍然是一项具有挑战性的任务。在本文中，我们报道了通过混合超表面实现宽带可见-近红外和深紫外产生，该超表面由等离子体纳米天线组成，其中嵌入了具有拉曼活性的金刚石纳米粒子作为例子。通过双色近红外泵浦调谐到拉曼共振，可以通过拉曼介质的相干调制产生主要由高阶受激拉曼散射贡献的可见-近红外频率梳，同时通过四波混频和三次谐波产生辐射宽带深紫外频率梳。在近红外区域，用峰值强度约为 33 GW cm-2、持续时间为 100 fs 的脉冲进行泵浦时，各个光谱峰的效率达到了 10-8-10-2%的量级。
