Enhanced optical Kerr nonlinearity of graphene/Si hybrid waveguide
Enhanced optical Kerr nonlinearity of graphene/Si hybrid waveguide
复制标题
石墨烯/硅混合波导的增强光学克尔非线性
DOI：
10.1063/1.5064832
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发表时间：
2019-02-18
影响因子：
4
通讯作者：
Zhang, Jianjun
中科院分区：
文献类型：
--
作者：
Feng, Qi;Cong, Hui;Zhang, Jianjun
在这项工作中，我们实验研究了增强自相位调制的石墨烯/硅混合波导的光学克尔非线性。在用于非线性光学信号处理的CMOS兼容材料的情况下，Si和氮化硅波导在过去十年中已经被广泛研究。然而，Si波导在通信波长处表现出强的双光子吸收（TPA），这导致非线性品质因数（FOM）的显著降低。相比之下，基于氮化硅的材料系统通常抑制TPA，但同时导致克尔非线性降低一个数量级。在这里，我们介绍了一种石墨烯/Si混合波导，它保持了Si波导的光学特性和CMOS兼容性，同时通过转移到波导的顶部来增强克尔非线性。石墨烯/硅波导的非线性系数为510 W-1 m（-1），而硅波导的非线性系数为150 W-1 m（-1）。已经实现了2.48 +/- 0.25的增强的非线性FOM，这是Si波导的0.6 +/- 0.1的四倍大。这项工作揭示了石墨烯/硅混合波导的潜在应用具有高克尔非线性和FOM的非线性全光信号处理。由AIP Publishing授权出版。
In this work, we experimentally study the optical Kerr nonlinearities of graphene/Si hybrid waveguides with enhanced self-phase modulation. In the case of CMOS compatible materials for nonlinear optical signal processing, Si and silicon nitride waveguides have been extensively investigated over the past decade. However, Si waveguides exhibit strong two-photon absorption (TPA) at telecommunication wavelengths, which leads to a significant reduction of the nonlinear figure-of-merit (FOM). In contrast, a silicon nitride based material system usually suppresses the TPA but simultaneously leads to the reduction of Kerr nonlinearity by one order of magnitude. Here, we introduce a graphene/Si hybrid waveguide, which maintains the optical properties and CMOS compatibility of Si waveguides, while enhancing the Kerr nonlinearity, by transferring over to the top of the waveguides. The graphene/Si waveguides are measured to have an enhanced nonlinear parameter of 510 W-1 m(-1), compared with that of the Si waveguide of 150 W-1 m(-1). An enhanced nonlinear FOM of 2.48 +/- 0.25 has been achieved, which is four times larger than that of the Si waveguide of 0.6 +/- 0.1. This work reveals the potential application of graphene/Si hybrid waveguides with high Kerr nonlinearity and FOM for nonlinear all-optical signal processing. Published under license by AIP Publishing.