Korean Researchers Develop ‘Nano-Lens’ (2009.7.23)
A team of multinational scientists developed a technique to produce tiny, nano-sized optical lenses, a breakthrough that may open new possibilities in microscopy and bio-imaging, the researchers said Wednesday.
In a study published in peer-review journal Nature, the researchers, led by Kwang Kim, a researcher from the Pohang University of Science and Technology (POSTECH), said they found that cup-shaped organic molecules, called calyx hydroquinone (CHQ), self-assemble into a lens shape when placed on a surface.
The nano-lenses produced in this way could push lens-based magnification to resolve features beyond the limits of diffraction, or the bending of light waves around small obstacles and the spreading of waves past small openings, Kim said.
Lens-based microscopes are constrained by the diffraction limit of light, which causes the final image to contain less information that what is present in the source.
Nano-lenses developed by Kim and his colleagues deflect light in curbed beams, in contrast to conventional optical lenses, resulting in very short focal lengths. This allows them to resovle features beyond the diffraction limit, enabling features of the order of 200 nano-meters or smaller to be resolved, Kim said.
“Such spherical nanolenses provide new pathways for lens-based near-field focusing and high-resolution optical imaging at very low intensities, which are useful for bio-imaging, near-field lithography, optical memory storage, light harvesting, spectral signal enhancing, and optical nano-sensing,” the researchers said in the paper published in Nature.
Kim’s work was funded by the Ministry of Education, Science and Technology’s “global research lab” project, and also participated by Columbia University’s Philip Kim, Laura Kaufman and Wong Chee Wei.