Improving the image quality of small particles is a classic problem and especially challenging when the distance between particles are below the optical diffraction limit. We propose a imaging system illuminated with radially polarized light combined with a suitable substrate that contains a thin dielectric layer to demonstrate that the imaging quality can be enhanced. The coupling between the evanescent wave produced in a designed thin dielectric layer, the small particles and the propagating wave forms a mechanism to transfer sub-wavelength information about the particles to the far field. The smallest distinguished distance reaches to 0.634λ, when the imaging system is composed of a high numerical aperture (NA=0.9) lens and the illumination wavelength λ = 632nm, beyond the diffraction limit 0.678λ. The lateral resolution can be further improved by combining the proposed structure with superresolution microscopy techniques.

中文翻译：

---

超薄效果归因于用于径向偏振光成像的薄介电平板。

改善小颗粒的图像质量是一个经典问题，当颗粒之间的距离低于光学衍射极限时，尤其具有挑战性。我们提出了一种成像系统，该成像系统用径向偏振光照射并与包含薄介电层的合适基板相结合，以证明可以提高成像质量。在设计的薄介电层中产生的e逝波，小颗粒与传播波之间的耦合形成了一种机制，可将有关颗粒的亚波长信息传输到远场。最小的分辨距离达到0.634 λ，当成像系统由高数值孔径的（NA = 0.9）透镜和照明波长λ = 632纳米，超越了衍射极限0.678 λ。通过将提出的结构与超分辨率显微镜技术相结合，可以进一步提高横向分辨率。