Hell Stefan W
Max-Planck-Institute for Biophysical Chemistry, Department of NanoBiophotonics, Am Fassberg 11, 37077 Göttingen, Germany.
Nat Biotechnol. 2003 Nov;21(11):1347-55. doi: 10.1038/nbt895.
For more than a century, the resolution of focusing light microscopy has been limited by diffraction to 180 nm in the focal plane and to 500 nm along the optic axis. Recently, microscopes have been reported that provide three- to sevenfold improved axial resolution in live cells. Moreover, a family of concepts has emerged that overcomes the diffraction barrier altogether. Its first exponent, stimulated emission depletion microscopy, has so far displayed a resolution down to 28 nm. Relying on saturated optical transitions, these concepts are limited only by the attainable saturation level. As strong saturation should be feasible at low light intensities, nanoscale imaging with focused light may be closer than ever.
一个多世纪以来，聚焦光学显微镜的分辨率受衍射限制，在焦平面上为180纳米，沿光轴为500纳米。最近，有报道称显微镜可使活细胞的轴向分辨率提高三到七倍。此外，还出现了一系列完全克服衍射障碍的概念。其首个范例——受激发射损耗显微镜，目前已实现低至28纳米的分辨率。这些概念依赖于饱和光学跃迁，仅受可达到的饱和水平限制。由于在低光强下实现强饱和应该是可行的，因此聚焦光纳米级成像可能比以往任何时候都更近一步。
