Rodrigues Janderson R, Dave Utsav D, Mohanty Aseema, Ji Xingchen, Datta Ipshita, Chaitanya Shriddha, Shim Euijae, Gutierrez-Jauregui Ricardo, Almeida Vilson R, Asenjo-Garcia Ana, Lipson Michal
Department of Electrical Engineering, Columbia University, New York, NY, 10027, USA.
Department of Electrical and Computer Engineering, Tufts University, Medford, MA, 02155, USA.
Nat Commun. 2023 Oct 21;14(1):6675. doi: 10.1038/s41467-023-42234-1.
Total internal reflection (TIR) governs the guiding mechanisms of almost all dielectric waveguides and therefore constrains most of the light in the material with the highest refractive index. The few options available to access the properties of lower-index materials include designs that are either lossy, periodic, exhibit limited optical bandwidth or are restricted to subwavelength modal volumes. Here, we propose and demonstrate a guiding mechanism that leverages symmetry in multilayer dielectric waveguides as well as evanescent fields to strongly confine light in low-index materials. The proposed waveguide structures exhibit unusual light properties, such as uniform field distribution with a non-Gaussian spatial profile and scale invariance of the optical mode. This guiding mechanism is general and can be further extended to various optical structures, employed for different polarizations, and in different spectral regions. Therefore, our results can have huge implications for integrated photonics and related technologies.
全内反射（TIR）支配着几乎所有介质波导的导光机制，因此将大部分光限制在折射率最高的材料中。用于获取低折射率材料特性的方法有限，包括有损、周期性、光学带宽有限或限于亚波长模态体积的设计。在此，我们提出并展示了一种导光机制，该机制利用多层介质波导中的对称性以及倏逝场，将光强烈限制在低折射率材料中。所提出的波导结构展现出不同寻常的光特性，例如具有非高斯空间分布的均匀场分布以及光学模式的尺度不变性。这种导光机制具有普遍性，可进一步扩展到各种光学结构，用于不同偏振以及不同光谱区域。因此，我们的结果可能对集成光子学及相关技术产生重大影响。
