High-performance waveguide-integrated Ge/Si avalanche photodetector with small contact angle between selectively epitaxial growth Ge and Si layers

Du Xiao-Qian^{1, 2}, Li Chong³, Li Ben³, Wang Nan^{1, 2}, Zhao Yue^{1, 2}, Yang Fan^{1, 2}, Yu Kai^{1, 2}, Zhou Lin^{1, 2}, Li Xiu-Li^{1, 2}, Cheng Bu-Wen^{1, 2}, Xue Chun-Lai^{1, 2, †}

Normalized RF response for (a) APD-3.0 and (b) APD-1.5 with 20- μ m -length structure at reverse bias of 15 V, 20 V, 23 V, and 25 V.