Anisotropy-free arrayed waveguide gratings on X-cut thin film lithium niobate platform of in-plane anisotropy oleh Junjie Yi, Changjian Guo, Ziliang Ruan, Gengxin Chen, Haiqiang Wei, Liwang Lu, Shengqi Gong, Xiaofu Pan, Xiaowan Shen, Xiaowei Guan, Daoxin Dai, Kangping Zhong, Liu Liu