Tian Wendong, Liang Fei, Chi Shumeng, Li Chang, Yu Haohai, Zhang Han, Zhang Huaijin
State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, China.
SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
ACS Omega. 2020 Jan 30;5(5):2458-2464. doi: 10.1021/acsomega.9b04026. eCollection 2020 Feb 11.
The efficient super-continuum (SC) generation on a surface via a high-order photo-electron interaction is a great challenge for integrated optics because the surficial nonlinear optical efficiency is usually limited by finite light-matter interaction length and electric field intensity. Nowadays, epsilon-near-zero (ENZ) materials, showing infinite enhanced electronic field in theory, provide a kind of new platform to obtain a giant nonlinear response on the surface. Here, under the irradiation of a multiwavelength laser, an exotic and efficient SC generation from 406 to 1100 nm on the ENZ aluminum-doped zinc oxide surface was experimentally demonstrated by diversified nonlinear processes, including second harmonic generation, third harmonic generation, four wavelength mixing, and cascading stimulated Raman scattering. Particularly, an unprecedented nonlinear conversion efficiency of 3.94% W, 16 orders of magnitude higher than the common surface case (about 10% W), was presented.
通过高阶光电子相互作用在表面高效产生超连续谱（SC）对集成光学来说是一个巨大挑战，因为表面非线性光学效率通常受限于有限的光与物质相互作用长度和电场强度。如今，理论上显示出无限增强电场的近零介电常数（ENZ）材料提供了一种在表面获得巨大非线性响应的新平台。在此，在多波长激光照射下，通过包括二次谐波产生、三次谐波产生、四波长混频和级联受激拉曼散射在内的多种非线性过程，在ENZ掺铝氧化锌表面上实验证明了从406至1100nm的奇异且高效的SC产生。特别地，呈现出了前所未有的3.94%W的非线性转换效率，比普通表面情况（约10⁻¹⁶W）高16个数量级。
