High-Speed Compact Plasmonic-PdSe₂ Waveguide-Integrated Photodetector

Waveguide-integrated photodetectors are essential components in integrated photonic circuits since they facilitate light conversion into electrical signals. Nonetheless, optical absorption and carrier collection can significantly affect the device performance. As a solution to this issue, plasmonic slot waveguides confine optical energy within a subwavelength scale in a photoconductive detector, enhancing optical absorption and providing extremely short channels to collect carriers. Two-dimensional van der Waals layered palladium selenide (PdSe2) exhibits the merits of a narrow bandgap and high carrier mobility, thus positioning it as a favorable candidate material for photodetectors operating at the telecommunication band. In this study, we propose and experimentally verify a high-speed PdSe2-plasmonic waveguide-integrated photodetector with a dark current of 4.5 mu A and an intrinsic responsivity of 560.1 mA center dot W-1 at 3 V. Additionally, it has an internal quantum efficiency of 32.3%, and the measured 3 dB bandwidth is 17.5 GHz. This integrated photodetector fulfills the requirements of various critical applications in optical communication, microwave photonics, sensing, and imaging.