ABSTRACT

Looking back, over the past 500 years, the resolution of the optical microscope was not improved in an order of magnitude after its invention because of the diffraction limit.

In order to break through such limit, in 1928, E. H. Synge published a paper in Philosophical Magazine titled “A suggested method for extending microscopic resolution into the ultra-microscopic region.” He proposed a new idea of microscope that could possibly achieve a resolution within 0.01 μm. However, the technology then available of mechanical precision and the intensity of light source was not advanced enough to satisfy the requirements for the new-type microscope. As a result, his paper was easily forgotten until the invention of the scanning near-fi eld optical microscope (SNOM).