Symmetric photodetector integrated with multilayer dielectric resonator cavity for 400 Gb/s optical communication system

The Multilayer Dielectric Resonator Cavity Symmetric Photodetector (MDRC-SPD) is designed and characterized. The photodetector possesses an InGaAs/InP symmetrical absorption structure bonded to the resonator cavity with Si/SiO2 reflector. These features alleviate the tradeoff between the 3 dB bandwidth and the quantum efficiency, and the 3 dB bandwidth of 41.3 GHz and the quantum efficiency of 0.92 are achieved. As a result, the optimal bandwidth-efficiency-product (BEP) and figure of merit (FOM) of the MDRC-SPD are 36.7 GHz and 14.6 dB at a reverse bias of 3 V, respectively, satisfies the requirements for the 400 Gb/s optical communication system using PAM4 modulation format.