Access to the complete spatiotemporal response of matter due to structured light requires field sampling techniques with sub-wavelength resolution in time and space. We demonstrate spatially resolved electro-optic sampling of near-infrared waveforms, providing a versatile platform for the direct measurement of electric field dynamics produced by photonic devices and sub-wavelength structures both in the far and near fields. This approach offers high-resolution, time- or frequency-resolved imaging by encoding a broadband signal into a narrowband blueshifted image, lifting the resolution limits imposed by both chromatic aberration and diffraction. Specifically, measuring the field of a near-infrared laser with a broadband sampling laser, we achieve 1.2 µm resolution in space and 2.2 fs resolution in time. This provides an essential diagnostic for complete spatiotemporal control of light with metasurface components, demonstrated via a metalens as well as a meta-axicon that forms broadband, ultrashort, truncated Bessel beams in the near infrared. Finally, we demonstrate the electric field dynamics of locally enhanced hot spots with sub-wavelength dimensions, recording the full temporal evolution of the electric field at each point in the image simultaneously. The imaging modality opens a path toward hyperspectral microscopy with simultaneous sub-wavelength resolution and wide-field imaging capability.

中文翻译：

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电场分辨近红外显微镜

由于结构光而获得物质的完整时空响应需要在时间和空间上具有亚波长分辨率的现场采样技术。我们展示了近红外波形的空间分辨电光采样，为直接测量由远场和近场中的光子器件和亚波长结构产生的电场动力学提供了一个多功能平台。这种方法通过将宽带信号编码到窄带蓝移图像中来提供高分辨率、时间或频率分辨的成像，从而提高色差和衍射所施加的分辨率限制。具体来说，使用宽带采样激光器测量近红外激光器的场，我们实现了 1.2 µm 的空间分辨率和 2.2 fs 的时间分辨率。这为具有超表面成分的光的完全时空控制提供了必要的诊断，通过超透镜以及在近红外中形成宽带、超短、截断贝塞尔光束的超轴棱镜来证明。最后，我们展示了具有亚波长尺寸的局部增强热点的电场动力学，同时记录了图像中每个点的电场的完整时间演化。成像方式为具有同时亚波长分辨率和宽视场成像能力的高光​​谱显微镜开辟了道路。我们展示了具有亚波长尺寸的局部增强热点的电场动力学，同时记录了图像中每个点的电场的完整时间演化。成像方式为具有同时亚波长分辨率和宽视场成像能力的高光​​谱显微镜开辟了道路。我们展示了具有亚波长尺寸的局部增强热点的电场动力学，同时记录了图像中每个点的电场的完整时间演化。成像方式为具有同时亚波长分辨率和宽视场成像能力的高光​​谱显微镜开辟了道路。