In this paper, we report a study on Si nanopatterns, fabricated as a one-dimensional (1D) Si nanograting with a sub-wavelength (≈200 nm) period. Unpolarized light normally incident on the nanopatterned Si becomes partially polarized and chiral over the entire visible range of 380–740 nm. The degree and the state of polarization of light were measured using polarimetric and ellipsometric techniques. The analysis showed that the reflected light is partially linearly polarized and at the same time a slight chirality (Ŝ₃≠0) is observed. Although the polarization of the reflected light is related to the 1D nanograting anisotropy, the chiral transformation of the light could be related to a micrometer-scale chiral substructure on the Si nanopatterned surface. This structure results from the dynamic polarization rotation of the femtosecond laser pulses in their filaments in liquid carbon disulfide near the Si surface during the interferential plasmonic self-organization of the surface nanorelief. These results could underline a key enabling process for the fabrication of polarization-sensitive metasurface-based sensors or devices within the common complementary metal-oxide semiconductor (CMOS)-compatible technology.

中文翻译：

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显示部分极化和手性的纳米图案硅

在本文中，我们报告了对 Si 纳米图案的研究，该图案制造为具有亚波长 (≈200 nm) 周期的一维 (1D) Si 纳米光栅。通常入射在纳米图案 Si 上的非偏振光在 380-740 nm 的整个可见光范围内变成部分偏振和手性光。使用偏振和椭偏技术测量光的偏振度和偏振状态。分析表明，反射光是部分线偏振的，同时具有轻微的手性（Ŝ ₃≠0) 被观察到。尽管反射光的偏振与一维纳米光栅各向异性有关，但光的手性转换可能与 Si 纳米图案表面上的微米级手性亚结构有关。这种结构是由飞秒激光脉冲在表面纳米浮雕的干涉等离子体自组织过程中在 Si 表面附近的液态二硫化碳中的细丝中的动态偏振旋转造成的。这些结果可以强调在通用互补金属氧化物半导体 (CMOS) 兼容技术中制造基于偏振敏感的超表面传感器或设备的关键使能过程。