This ultra-thin surface controls light in two completely different ways
This ultra-thin surface controls light in two completely different ways A new metasurface design lets light of different spins bend, focus, and behave independently—while staying sharp across many colors. The trick combines two geometric phase effects so each spin channel can be tuned without interfering with the other. Researchers demonstrated stable beam steering and dual-focus lenses over wide frequency ranges. The approach could scale from microwaves all the way to visible light. The achromatic lens can focus the incident RCP and LCP light onto two distinct positions without chromatic aberration over a wide bandwidth. Credit: School of Electronic Science and Engineering, Nanjing University Broadband achromatic wavefront control is a key requirement for next-generation optical technologies, including full-color imaging and multi-spectral sensing. Researchers led by Professor Yijun Feng and Professor Ke Chen at Nanjing University have now reported a major advance in this area in Phot...