Study and fabrication of MMI optical power splitter based on the proton exchange of LiNbO₃

LiNbO₃ proton exchanged 1 × 4 MMI power splitters have been designed and fabricated. The MMI optical power splitters based on the self-imaging effect (SIE) have been analyzed, and an 1 × 4 MMI power splitter designed. The designed device is simulated and optimized with Beamprop software, and the simulation results were basically in agreement with the designed effect. The excess loss induced by multimode interference was less than 0.04 dB, and the uniformity about 0.01 dB. The low loss and fine uniformity MMI power splitter has been made by the Lithium Niobate annealed proton exchange technology, and experimental sample measurement results were achieved.