A novel beam splitter based on graded photonic crystals

This study proposes a novel beam splitter system based on graded photonic crystals, wherein the GPCs are part of a circular PC. A self-collimating PC structure with a square lattice is added to improve transmissivity. The total transmissivity is increased by extending the defect of the self-collimating PC. This study presents a beam splitter system with low energy loss and the best total transmissivity of almost 90%. Furthermore, the relationship between the beam-splitting ratio and the light position is discovered, and the beam-splitting ratio may be changed discretionarily and expediently. Numerical results are obtained using finite-difference time domain and plane wave methods. The proposed structure has significant application potential in optical integration.