High-Speed 46-GHz 850 nm Photodetector With Inductive Peaking

In this work, high-speed 850 nm GaAs/AlGaAs based dual-depletion-region photodetectors are demonstrated, which aim to meet the increasing need for bandwidth scaling and data rate in short-reach optical links. The devices exhibit the low dark current of similar to 134.5 fA and responsivity of similar to 0.44 A/W at 850 nm. The 3-dB bandwidth of 20 mu m and 28 mu m diameter devices with 50-ohm characteristic impedance transmission line were measured to be 29.72 GHz and 24.71 GHz respectively. While by incorporating inductive peaking via high characteristic impedance transmission line, the 20 mu m and 28 mu m diameter devices achieved maximum 3-dB bandwidth of 46.06 GHz and 36.09 GHz respectively. To the best of our knowledge, this 20 mu m diameter device exhibits the highest 3-dB bandwidth among all the 850 nm photodetectors. This research showcases the potential of 850 nm dual-depletion-region photodetectors as promising solutions for high-speed short-reach optical communication systems, offering improved performance in terms of bandwidth and enabling the advancement of data transmission capabilities.