Design of uni-traveling-carrier photodiode with nanoscale optical microstructures

In this article, we report a uni-traveling-carrier photodiode (UTC-PD) incorporating nanoscale optical microstructures. We have designed a UTC-PD incorporating a core-cladding confinement structure, which incorporates internal optical scattering structures to convert incident light from vertical incidence to lateral propagation, and to as much as possible confine light within the absorption layer of the UTC-PD. In this way, the proposed UTC-PD can have an operating performance like that of a waveguide-type PD under vertical light incidence, and its responsivity will increase. The ideal responsivity of the designed UTC-PD with an absorption layer thickness of 200nm after optimization can reach 0.43 A/W, which is 48 % higher than that of the traditional structure.