Evanescent wave enabled broadband superresolution microlens arrays with large-area and wide-angle field of view
Yang Tsao1,2*, Yun-Ju Liu1, Zong-Xing Lou1,2, Pin-Yi Li1,2, Kuan-Yu Li1, Wei-Li Lee3, Shi-Wei Chu1, Chih-Wei Chang2
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
3Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:曹陽, email:damlytohot@yahoo.com.tw
The resolution of conventional microscope is restricted to λ/2 by the Abbe diffraction limit. There are some approaches to overcome the diffraction limit nowadays, e.g. near-field scanning optical microscopy, fluorescent microscopy, and negative index materials, etc. However, these techniques suffer by slow scanning speeds, short-lifetime of fluorescent dyes, and sophisticated fabrication processes. Recently, it has been shown that dielectric microspheres can bring the sub-wavelength information to far-field, achieving superresolution using a white-light source. Here, we demonstrate a transferable microspheres arrays reaching spatial resolution at least λ/4.5. The microspheres are capable of offering large field of view, wide angle, and polarization-independent images. We also provide evidence that the superresolution mechanism is due to evanescent waves. We further study the effects of resonant whispering gallery modes to images.

Keywords: superresolution, whispering gallery mode, diffraction limit, evanescent wave, microscopy