Terahertz imaging through emissivity control
Terahertz imaging through emissivity control
复制标题
DOI：
10.1364/optica.503936
复制
发表时间：
2023-08
期刊：
影响因子：
10.4
通讯作者：
M. Mrnka;H. Penketh;I. Hooper;S. Saxena;N. Grant;J. Murphy;David B. Phillips;E. Hendry
中科院分区：
文献类型：
--
作者：
M. Mrnka;H. Penketh;I. Hooper;S. Saxena;N. Grant;J. Murphy;David B. Phillips;E. Hendry
太赫兹技术的采用受到缺乏具有成本效益的太赫兹源的阻碍。在这里，我们展示了一种全新的方式来产生和控制太赫兹辐射，通过时空发射率调制。通过图案化的表面钝化的硅晶片的光激发，我们局部控制的自由电子密度，从而图案化的电磁波谱的太赫兹部分的晶片的发射率。我们展示了这种非常规的可控太赫兹辐射源如何实现一种新形式的非相干计算太赫兹成像。我们用它来成像各种隐藏的目标，证明了这种方案具有穿透能力的最先进的太赫兹成像方法，而不需要飞秒脉冲激光源。此外，热辐射的非相干性质也确保所获得的图像没有干扰伪影。我们的时空发射率控制为新的长波长结构化照明、成像和光谱系统家族铺平了道路。
Adoption of terahertz technologies is hindered by the lack of cost-effective THz sources. Here we demonstrate a fundamentally new way to generate and control THz radiation, via spatio-temporal emissivity modulation. By patterning the optical photoexcitation of a surface-passivated silicon wafer, we locally control the free-electron density, and thereby pattern the wafer's emissivity in the THz part of the electromagnetic spectrum. We show how this unconventional source of controllable THz radiation enables a new form of incoherent computational THz imaging. We use it to image various concealed objects, demonstrating this scheme has the penetrating capability of state-of-the-art THz imaging approaches, without the requirement of femto-second pulsed laser sources. Furthermore, the incoherent nature of thermal radiation also ensures the obtained images are free of interference artifacts. Our spatio-temporal emissivity control paves the way towards a new family of long-wavelength structured illumination, imaging and spectroscopy systems.