Trapezoidal dual-function splitter under second Bragg incidence.

In this paper, a reflective trapezoidal dual-functional beam splitter grating is proposed, which performs two independent functions at 1550 nm. For TE polarization, the grating can achieve a uniform three-port output with efficiencies of 32.85%, 32.89%, and 32.75% for 0th, -1st, and -2nd orders respectively. For TM polarization, the grating can achieve a highly-efficient single-channel output of order -2nd with an efficiency of 93.27%. HfO 2 is chosen as the material of grating ridge layer, the structural parameters of the grating are studied by using rigorous coupled-wave analysis (RCWA) and simulated annealing algorithm (SAA), and the results are verified by using finite element method (FEM). In addition, the influence of structure and incident error on grating efficiency was also analyzed, the results indicate that the grating has good incident bandwidth and manufacturing tolerance with excellent performance. • Trapezoidal dual-functional splitter with two reflective independent functions. • For TE polarization, a uniform three-port with efficiencies of 32.85%, 32.89%, and 32.75% for 0th, -1st, and -2nd orders. • For TM polarization, a highly-efficient single-channel output of order -2nd with an efficiency of 93.27%. [ABSTRACT FROM AUTHOR]