NYU Chemistry Professors Bart Kahr and Michael D. Ward report new findings in the Proceedings of the National Academy of Sciences (PNAS, October 7, 2013 doi:10.1073) in a study called, "Illusory Spirals and Loops in Crystal Growth."
A computer-generated hologram projects a beam of light that focuses to interlocking inclined rings, a simple knot known as a Hopf link. Each ring acts as an optical trap that can gather and hold micrometer-scale objects. The same hologram also imposes phase gradients around the Hopf link, thereby creating a knot in the total optical force field.
Research Experiences for Undergraduates (REU) fellowships are awarded to undergraduates from four-year colleges and universities for participation in a ten-week summer program. Students enjoy innovative research, professional development, and social activities all in the heart of New York City.