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 ...

Vortex phenomena are widespread in nature, from typhoons to ocean currents. In the field of optics, vortex beams, which carry orbital angular ...