Improve polarization topological order sorting with the diffractive splitting method.

Vector beams with different polarization topological orders (PTOs) are the eigenmodes of traditional optical fibers and are orthogonal to each other, so the PTO multiplexing channel is a promising candidate for the oncoming generation of optical communication. Here we demonstrate experimentally a PTO sorting system with high separation resolution based on the diffractive splitting (DS) method. Our experiments show that our design with the DS method helps to enhance the separation resolution to 77.5% from 58%, compared to a design without the application of a DS method. Theoretically, to increase the copy number can promote the separation resolution further. This Letter provides a high-resolution way to decode information from PTO division multiplexing.