High-responsivity on-chip waveguide coupled germanium photodetector for 2 μm waveband  

作　　者：JIANING WANG XI WANG YIHANG LI YANFU YANG QINGHAI SONG KE XU 

机构地区：[1]Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems,Harbin Institute of Technology,Shenzhen 518055,China [2]Department of Electronic&Information Engineering,Harbin Institute of Technology,Shenzhen 518055,China [3]Department of Science,Harbin Institute of Technology,Shenzhen 518055,China

出　　处：《Photonics Research》2024年第1期115-122,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(U21A20454);Science,Technology and Innovation Commission of Shenzhen Municipality (JCYJ20220818102406013,RCYX20210609103707009);Natural Science Foundation of Guangdong Province for Distinguished Young Scholars(2022B1515020057)。

摘　　要：Recently,the emerging 2μm waveband has gained increasing interest due to its great potential for a wide scope of applications.Compared with the existing optical communication windows at shorter wavelengths,it also offers distinct advantages of lower nonlinear absorption,better fabrication tolerance,and larger free carrier plasma effects for silicon photonics,which has been a proven device technology.While much progress has been witnessed for silicon photonics at the 2μm waveband,the primary challenge still exists for on-chip detectors.Despite the maturity and compatibility of the waveguide coupled photodetectors made of germanium,the 2μm regime is far beyond its cutoff wavelength.In this work,we demonstrate an efficient and high-speed on-chip waveguidecoupled germanium photodetector operating at the 2μm waveband.The weak sub-bandgap absorption of epitaxial germanium is greatly enhanced by a lateral separation absorption charge multiplication structure.The detector is fabricated by the standard process offered by a commercial foundry.The device has a benchmark performance with responsivity of 1.05 A/W and 3 dB bandwidth of 7.12 GHz,which is able to receive high-speed signals with up to 20 Gbit/s data rate.The availability of such an efficient and fast on-chip detector circumvents the barriers between silicon photonic integrated circuits and the potential applications at the 2μm waveband.

关 键 词：WAVEGUIDE RESPONSIVITY WAVE 

分 类 号：TN36[电子电信—物理电子学]