Polarization-Insensitive Y-Junction Power Splitter on Lithium Niobate-on-Insulator Platform

The optical power splitter is one of the crucial components of photonics integrated circuits. In this paper, we propose and demonstrate a broadband, compact and polarization-insensitive Y-junction power splitter based on the lithium niobate-on-insulator (LNOI) platform. This device employs an adiabatic coupling structure to achieve a 1:1 power distribution for both TE polarization and TM polarization. Experimental results show that in the wavelength of 1506-1615 nm, the insertion loss of this device is less than 0.7 dB and 0.5 dB for the TE0and TM0modes, respectively. Meanwhile, the polarization dependence loss is less than ±0.5dB. The proposed device can be applied to future high-density photonic integrated links.