527.8km ultra-long single span distributed optical sensing with Co-Propagating 400Gb/s optical transmission. - Jian Xu; Ming Li; William Shieh; Qi Yang 001; Dajun Long; Qianggao Hu; Jiekui Yu; Chen Liu; Zhenyu Zhu; Xiaoyu Wang; Mingxiong Duan; Guangli Pan; et al. (OFC, 2025)