"The resolution of most optical microscopes is restricted by the so-called ‘diffraction limit,’ which means we cannot produce optical images with resolutions higher than a few hundred nanometers," Xu said. "Currently, the most advanced optical microscope can achieve a resolution only as low as 50 nanometers."
In the field of nanotechnology, researchers are discovering ways to arrange atoms into unique structures on the molecular scale. Xu is attempting to produce an optical microscope that can observe nanostructures at a resolution of one nanometer — which is equal in size to approximately one-billionth of a meter, or the diameter of four atoms.
In addition to achieving a breakthrough in arranging nanostructures, Xu hopes that his research will lead to observation of the "vacuum field" at a resolution of one nanometer.
"Vacuum field refers to the tiny amount of electric field fluctuations that can exist in the absence of any sources such as electrons or atoms," Xu explained. "Even though vacuum field cannot be directly measured, without it no light source can emit light. Observing the vacuum field at one nanometer resolution would help scientists solve one of the few remaining mysteries of quantum electrodynamics."
All of this, Xu believes, can ultimately lead to chip-scale quantum information processing and can help boost the pace of discovery in nanophotonics research and engineering.
Previous coverage on this site about creating superlenses with metamaterials to try to get to 17 nanometers with optical wavelengths and to 6 to 16 nanometers with soft x rays and 60 nanometers with a plasmon microscope
Near field optical microscopes can differentiate between objects less than 10 nanometers apart