Tolerance Analysis of Optical splitter / combiner on Lithium Niobate Modulator

In this work, we compare the impact of fabrication errors on crucial parameters in the Y-branch and the Multimode Interference (MMI) coupler using simulation software.Relative error and absolute error are considered to evaluate the device's tolerance performance. The results show that the use of MMI devices as splitters and combiners in lithium niobate (LN) Modulators has greater advantages in terms of fabrication errors.