Abstract High-efficiency and high-speed photodetectors with broadband responses are playing pivotal roles for wavelength-division multiplexing optical communications. Germanium photodetectors on silicon platforms exhibit potential cost advantage due to the compatibility for monolithic integration with silicon-based electronic circuits for signal amplification and processing. In this article, we report a normal incidence, germanium photodetector enabled by guided-mode resonances in photonic crystal, which successfully resolved the compromise between quantum efficiency, wavelength coverage and bandwidth requirement, a drawback usually faced by conventional photodetectors operating at normal incidence. The resonant photonic crystal structure is designed to support multiple resonances in the target wavelength range. With an intrinsic absorption layer thickness of 350 nm, the device achieved a high external quantum efficiency of 50% at 1550 nm, along with an enhancement around 300% for the entire C-band. Using a mesa diameter of 14 μm, the fabricated device exhibited a 3-dB bandwidth of 33 GHz and obtained clear eye diagrams at bit rate up to 56 Gbps. This work provides a promising method to design high-efficiency, high-speed, normal incidence germanium photodetectors for optical interconnect systems.

中文翻译：

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多谐振光子晶体实现的高效高速锗光电探测器

摘要 具有宽带响应的高效高速光电探测器在波分复用光通信中发挥着举足轻重的作用。由于与用于信号放大和处理的硅基电子电路的单片集成兼容性，硅平台上的锗光电探测器表现出潜在的成本优势。在本文中，我们报告了一种由光子晶体中的导模共振实现的垂直入射锗光电探测器，它成功地解决了量子效率、波长覆盖范围和带宽要求之间的折衷问题，这是传统光电探测器在垂直入射下通常面临的一个缺点。谐振光子晶体结构旨在支持目标波长范围内的多个谐振。凭借 350 nm 的本征吸收层厚度，该器件在 1550 nm 处实现了 50% 的高外部量子效率，同时整个 C 波段的增强率提高了约 300%。使用 14 μm 的台面直径，制造的设备表现出 33 GHz 的 3 dB 带宽，并在高达 56 Gbps 的比特率下获得清晰的眼图。这项工作为设计用于光互连系统的高效、高速、法向入射锗光电探测器提供了一种很有前景的方法。