近日，华中科技大学的张新亮&余宇及其研究团队取得一项新进展。经过不懈努力，他们研制出1033GHz超高增益带宽积的雪崩光电二极管。相关研究成果已于2024年4月9日在国际知名学术期刊《自然—光子学》上发表。

该研究团队实现了一个锗/硅APD,其GBP突破了1THz大关。这一创新成果得益于两种精心设计的合作策略：精确塑造电场分布和精心优化雪崩过程中的谐振效应。实验数据显示，该APD在单位增益下的主响应率高达0.87AW^-1，同时在9-19.5增益范围内展现出53GHz的宽频带特性。在8.6V的偏置电压和1550nm的波长下，其GBP更是高达1033 GHz。

为了验证该APD的实用性，研究团队在眼图清晰、灵敏度高的条件下，成功实现了每波长112Gbs^-1的开关键控信号和200Gbs^-1的四电平脉冲调幅信号的数据接收，并通过四通道实现了800G的接收。这一成果为下一代光互连中的高速光电器件提供了极具潜力的继任者。

据悉，雪崩光电二极管(APDs)在光通信、传感和量子应用中实现了高灵敏度的光探测。在提高增益-带宽乘积(GBP)方面已经付出了巨大的努力。然而，由于未能全面考虑雪崩过程的复杂性，进一步的进展遇到了巨大的障碍。

附：英文原文

Title: Avalanche photodiode with ultrahigh gain–bandwidth product of 1,033 GHz

Author: Shi, Yang, Li, Xiang, Chen, Guanyu, Zou, Mingjie, Cai, Hongjun, Yu, Yu, Zhang, Xinliang

Issue&Volume: 2024-04-09

Abstract: Avalanche photodiodes (APDs) have enabled highly sensitive photodetection in optical communication, sensing and quantum applications. Great efforts have been focused on improving their gain–bandwidth product (GBP). However, further advance has encountered enormous barriers due to incomplete consideration of the avalanche process. Here we implement a germanium/silicon APD with the GBP breaking through 1THz. The performance is achieved by introducing two cooperative strategies: precisely shaping the electric field distribution and elaborately engineering the resonant effect in the avalanche process. Experimentally, the presented APD has a primary responsivity of 0.87AW^-1 at unity gain, a large bandwidth of 53GHz in the gain range of 9–19.5 and an ultrahigh GBP of 1,033GHz under 8.6V and at 1,550nm. For demonstration, data reception of 112Gbs^-1 on–off keying and 200Gbs^-1 four-level pulse amplitude modulation signals per wavelength are achieved with clear eye diagrams and high sensitivity, as well as 800G reception via four channels. This work provides a potential successor for high-speed optoelectronic devices in next-generation optical interconnects.

DOI: 10.1038/s41566-024-01421-2

Source: https://www.nature.com/articles/s41566-024-01421-2