Ultrafast sub-30-fs all-optical switching based on gallium phosphide
Ultrafast sub-30-fs all-optical switching based on gallium phosphide
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DOI：
10.1126/sciadv.aaw3262
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发表时间：
2019-06-01
期刊：
影响因子：
13.6
通讯作者：
Maier, Stefan A.
中科院分区：
文献类型：
--
作者：
Grinblat, Gustavo;Nielsen, Michael P.;Maier, Stefan A.
磷化镓（GaP）是少数几种在可见光（λ> 450 nm）和近红外区具有强光学非线性和可忽略损失的可用材料之一。在这项工作中，我们证明了磷化镓膜可以产生sub 30- fs（半高全宽）的传输调制高达70%，在600- 1000 nm的波长范围内。利用Z扫描方法测量的参数进行的非线性模拟表明，透射调制来自于光学克尔效应和双光子吸收。由于没有线性吸收，没有检测到较慢的自由载流子贡献。这些发现将GaP作为一种有前途的超快材料，用于调制速度高达20 THz的全光开关。
Gallium phosphide (GaP) is one of the few available materials with strong optical nonlinearity and negligible losses in the visible (lambda > 450 nm) and near-infrared regime. In this work, we demonstrate that a GaP film can generate sub30- fs (full width at half maximum) transmission modulation of up to similar to 70% in the 600- to 1000-nm wavelength range. Nonlinear simulations using parameters measured by the Z-scan approach indicate that the transmission modulation arises from the optical Kerr effect and two-photon absorption. Because of the absence of linear absorption, no slower free-carrier contribution is detected. These findings place GaP as a promising ultrafast material for all-optical switching at modulation speeds of up to 20 THz.