Nonlinear Fano-Resonant Dielectric Metasurfaces

详细信息    查看全文

• 作者：Yuanmu Yang ; Wenyi Wang ; Abdelaziz Boulesbaa ; Ivan I. Kravchenko ; Dayrl P. Briggs ; Alexander Puretzky ; David Geohegan ; Jason Valentine
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：November 11, 2015
• 年：2015
• 卷：15
• 期：11
• 页码：7388-7393
• 全文大小：414K
• ISSN：1530-6992

文摘

Strong nonlinear light鈥搈atter interaction is highly sought-after for a variety of applications including lasing and all-optical light modulation. Recently, resonant plasmonic structures have been considered promising candidates for enhancing nonlinear optical processes due to their ability to greatly enhance the optical near-field; however, their small mode volumes prevent the inherently large nonlinear susceptibility of the metal from being efficiently exploited. Here, we present an alternative approach that utilizes a Fano-resonant silicon metasurface. The metasurface results in strong near-field enhancement within the volume of the silicon resonator while minimizing two photon absorption. We measure a third harmonic generation enhancement factor of 1.5 脳 10⁵ with respect to an unpatterned silicon film and an absolute conversion efficiency of 1.2 脳 10^鈥? with a peak pump intensity of 3.2 GW cm^鈥?. The enhanced nonlinearity, combined with a sharp linear transmittance spectrum, results in transmission modulation with a modulation depth of 36%. The modulation mechanism is studied by pump鈥損robe experiments.