Fig. 1. Basic physical structure of MPLC

Fig. 2. Design process of phase plates in MPLC

Fig. 3. Results of 16-channel CBC by MPLC. (a) Complex amplitude of electric fields before and after phase modulation at each plane; (b) phase modulation values at each plane; (c) beam size variations in the process of propagation

Fig. 4. Average coupling efficiency with respect to plane count in 16-channel mode multiplexing by MPLC

Fig. 5. Results of 16-channel mode multiplexing by MPLC. (a) Coupling coefficient in the process of iteration; (b) transmission matrix of modes; (c) values of phase modulation at each plane; (d) 16 HG modes obtained

Fig. 6. Steering obtained by decomposing finite modes. (a) Steering efficiency by decomposing different numbers of HG modes; (b) steering efficiency by decomposing different numbers of LG modes

Fig. 7. Steering performances of 3 CBC systems. (a) Steering efficiency at various tilt angles; (b) far-field patterns of combined beam in 3 CBC systems at various tilt angles