Thinfilm lithium niobate 3-dB power splitter with ultrabroadband bandwidth from 1.2 to 2 µm

We experimentally demonstrate a 3-dB power splitter based on adiabatic mode evolution using thin-film lithium niobate, with ultra-broadband operation bandwidth. The fabricated power splitter exhibits low insertion losses of 0.2 dB, 0.16 dB, and 0.53 dB for wavelengths at 1310, 1550, and 2000 nm, respectively.