Coupling mechanism and field distribution of reflective grating for 1×5 splitting

Abstract In order to design a five-port grating with good uniformity, a single-groove reflective beam splitter with an incident wavelength of 1550 nm is designed. The incident structure is under normal incidence. We get better optimized parameters by rigorous coupled waves. The five diffraction order efficiencies of the grating are each close to 20%. The optimized data shows that grating structure has high efficiency and high tolerance, which will have good application value in the field of beam splitter. Furthermore, by investigating the coupling overlap integration and field distribution, the mechanism can be well explained for such a grating.