High-Speed Evanescently-Coupled Waveguide Type-II MUTC Photodiodes for Zero-Bias Operation
Fengxin Yu, Keye Sun, Qianhuan Yu, Andréas Beling
Abstract
We demonstrate evanescently-coupled GaAs <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> /In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.53</sub> AlyGa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.47-y</sub> As modified uni-traveling carrier (MUTC) waveguide photodiodes (PDs) with high bandwidth (BW) of 66 GHz at zero bias and over 100 GHz bandwidth under low bias condition. An In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x-y</sub> As dual-integrated waveguide-drift layer which can facilitate efficient light coupling from the waveguide into the absorber over a short length is utilized. A 7-μm long waveguide PD has an internal responsivity of 0.48 A/W at 1550 nm and clearly open eye diagrams at 40 Gb/s are demonstrated at zero bias.