Investigating the Mechanism of Superresolution of Dielectric Microspheres
| Autor: | Pin-Yi Li, 李品儀 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Superresolution techniques are widely-used approaches to overcome diffraction limit. However, those techniques encounter difficulties, such as sluggish scanning speeds, limited lifetime of fluorescent dyes, or sophisticated fabrication processes. Recently, it has been shown that dielectric microspheres can bring the sub-wavelength information to far-field, achieving superresolution by a white-light source. Indeed, we have also demonstrated that it can reach spatial resolution better than λ/6.4 using the microspheres. However, the underlying mechanism of microsphere superresolution is still under debate. Two possible mechanisms are whispering gallery modes and evanescent waves. In this thesis, we experimentally exclude the two mechanisms be likely explanations. Instead, we propose and demonstrate coupling-induced coherent superresolution to be the mechanism for enhancement of resolution. We further show evidence that by combining the coupling-induced coherent superresolution and microsphere can drastically increase the resolution when imaging metallic and nonmetallic samples. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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