'Groovy' hologram creates strange state of light at visible and invisible wavelengths | Wyly Wade
Applied physicists at the Harvard School of Engineering and Applied Sciences (SEAS) have demonstrated that they can change the intensity, phase, and polarization of light rays using a hologram-like design decorated with nanoscale structures. As a proof of principle, the researchers have used it to create an unusual state of light called a radially polarized beam, which—because it can be focused very tightly—is important for applications like high-resolution lithography and for trapping and manipulating tiny particles like viruses. "Our lab works on using nanotechnology to play with light," says Patrice Genevet, a research associate at Harvard SEAS and co-lead author of a paper published this month in Nano Letters. "In this research, we've used holography in a novel way, incorporating cutting-edge nanotechnology in the form of subwavelength structures at a scale of just tens of nanometers." One nanometer equals one billionth of a meter.