Super-resolution optical nano imaging through transparent microsphere (Conference Presentation)

Abstract

Pushing the resolution limit of the optical microscope beyond 100 nm is revolutionary in the field of super-resolution imaging. It has been demonstrated that when a dielectric transparent microsphere at a diameter of a few microns is located between the sample and objective lens, its resolution can be enhanced. In this talk, both contact and non-contact modes of the microsphere optical super-resolution imaging are presented. In the contact mode, where the microsphere is in touch with the sample surface, fine features with the size of 38 nm can be observed. However, the contact mode has a critical drawback that the relative location of the microsphere and sample cannot be adjusted, thus limiting the imaging field and contaminating the sample surface. To address this issue, a non-contact scanning mode of the microsphere super-resolution imaging is developed by attaching the high refractive index microsphere onto thin glass substrate and control the movement of the microsphere by a nano-stage. The gap between the sample and microsphere is around a few microns in the oil immersion condition. Features with the size of 75 nm can be observed by the non-contact scanning mode of the microsphere under a conventional optical microscope. The resolution is expected to be higher when the microsphere is engineered with micron size structures on the surface.