“…[3][4][5][6][7][8][9] Beam-splitting structures are the key building blocks in optical integration devices, so numerous beam-splitting structures based on PCs have been presented. [10][11][12][13][14][15][16][17][18][19][20][21][22] Several methods have been studied to realize the beam-splitting phenomenon, including photonic band gap, 10,19,20 directional coupling, 11,14,15 defects 12 and self-collimation. 13,16,17 However, the splitting efficiencies achieved by these methods are low, and the splitting ratio cannot be changed discretionarily.…”