Abstract：
The development of super-resolution fluorescence microscopy is very essential for understanding the physical and biological fundamentals at nanometer scale. However, to date most super-resolution modalities require either complicated/costly purpose-built systems such as multiple-beam architectures or complex post-processing procedures with intrinsic artifacts. Achieving three-dimensional (3D) or multi-channel sub-diffraction microscopic imaging using a simple method remains a challenging and struggling task. Herein, we proposed 3D highly-nonlinear super-resolution microscopy using a single-beam excitation strategy, and the microscopy principle was modelled and studied based on the ultrahigh nonlinearity enabled by photon avalanches. According to the simulation, the point spread function of highly nonlinear microscopy is switchable among different modes and can shrink three-dimensionally to sub-diffraction scale at the photon avalanche mode. Experimentally, we demonstrated 3D optical nanoscopy assisted with huge optical nonlinearities in a simple laser scanning configuration, achieving a lateral resolution down to 58 nm (λ/14) and an axial resolution down to 185 nm (λ/5) with one single beam of low-power, continuous-wave, near-infrared laser. We further extended the photon avalanche effect to many other emitters to develop multi-color photon avalanching nanoprobes based on migrating photon avalanche mechanism, which enables us to implement single-beam dual-color sub-diffraction super-resolution microscopic imaging.
摘要：
超分辨率荧光显微镜的发展对于理解纳米尺度的物理和生物学基础非常重要。然而,迄今为止，大多数超分辨率模式都需要复杂/昂贵的专用系统，例如多波束架构或具有固有伪影的复杂后处理程序。使用简单方法实现三维(3D)或多通道亚衍射显微成像仍然是一项具有挑战性和困难的任务。在这里，我们提出了使用单光束激发策略的3D高度非线性超分辨率显微镜，基于光子雪崩实现的超高非线性，对显微镜原理进行了建模和研究。根据模拟,高度非线性显微镜的点扩散函数可以在不同模式之间切换，并且可以在光子雪崩模式下三维缩小到亚衍射尺度。实验上,我们在简单的激光扫描配置中展示了3D光学纳米显微镜辅助巨大的光学非线性，实现横向分辨率低至58nm（λ/14）和轴向分辨率低至185nm（λ/5）与一个单一的低功率光束，连续波，近红外激光。我们进一步将光子雪崩效应扩展到许多其他发射器，以开发基于迁移光子雪崩机制的多色光子雪崩纳米探针，这使我们能够实现单光束双色亚衍射超分辨率显微成像。
