Super-resolution microscopy: better resolution and richer information

Peng Xi^1*

¹Department of Biomedical Engineering, Peking University, Beijing, China

* Presenter:Peng Xi, email:xipeng@pku.edu.cn

The resolution of conventional optical microscopy is ~200 nm, which limits the biological research to visualize clearly the subcellular organelles. To overcome this, different super-resolution techniques have been raised. Of them, stimulated emission depletion (STED) microscopy employs a donut-beam confined excitation to project an optically saturated virtual pinhole for super-resolution. STED microscopy often obeys a “square-root law” for resolution and STED laser power, which means the power increases quadratically for better resolution. This approach, although working well in principle, is practically limited by the fragileness of the biological subcellular structure, as well as the photostability of the dye.
Here we present several novel techniques:
(1) Mirror enhanced axial narrowing super-resolution microscopy (MEANS), aiming at improving both the axial and lateral resolution of a conventional STED microscopy, yet without increasing the STED laser power.
(2) Upconversion enabled ultralow power STED. Owing to the rich energy levels, we can create unique “route” for its pump-probve process, thus ultralow power STED can be realized.
(3) Super-resolution dipole orientation microscopy, in which the dipole orientation can be employed to improve the resolution. Moreover, the dipole orientation information provides a new dimension for super-resolution.

Keywords: STED, dipole, interference, axial