High common mode rejection ratio InP 90° optical hybrid in ultra-broadband at 60 nm with deep-rigded waveguide based on × 4 MMI coupler
Lu Zi-Qing1, 2, Han Qin1, 2, 3, †, Ye Han1, 2, Wang Shuai1, 2, Xiao Feng1, 2, Xiao Fan1, 2
       

Simulated phase deviation of designed 90° hybrid.