The PBG group of Department of physics, Fudan university, recently proposed a method using a reflective photonic crystal slab to generate vortex with high conversion efficiency and without an ...

Imagine a whirlpool spinning in a river, or a tornado swirling through the sky. They don't just spin on the spot: they travel forward while maintaining that spiraling motion inside them. These ...

As a new degree of freedom, the orbital angular momentum of electromagnetic waves exceeds the traditional frequency, phase, and amplitude, and is expected to promote the infinite expansion of channel ...