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-Qing^{1, 2}, Han Qin^{1, 2, 3, †}, Ye Han^{1, 2}, Wang Shuai^{1, 2}, Xiao Feng^{1, 2}, Xiao Fan^{1, 2}

Simulated phase deviations of InP 90° hybrid varying with MMI width at 1550 nm for Ch-2 to Ch-1, Ch-3 to Ch-1, and Ch-4 to Ch-1, respectively.