High speed optical modulation in Ge quantum wells using quantum confined stark effect  

作　　者：Yiwen RONG Yijie HUO Edward T.FE Marco FIORENTINO Michael R.T.TAN Tomasz OCHALSKI Guillaume HUYET Lars THYLEN Marek CHACINSKI Theodore I.KAMINS James S.HARRIS 

机构地区：[1]Department of Electrical Engineering,Stanford University,Stanford,CA 94305,USA [2]Quantum Science Research,Hewlett-Packard Laboratories,Palo Alto,CA 94304,USA [3]Tyndall National Institute,Lee Maltings,Photonics Building,Cork,Ireland [4]Photonics and Microwave Engineering Royal Institute of Technology Kista,Stockholm S-16440,Sweden

出　　处：《Frontiers of Optoelectronics》2012年第1期82-89,共8页光电子前沿（英文版）

摘　　要：We focus on the optimization of SiGe material deposition, the minimization of the parasitic capacitance of the probe pads for high speed, low voltage and high contrast ratio operation. The device fabrication is based on processes for standard Si electronics and is suitable for mass-production. We present observations of quantum confinement and quantum-confined Stark effect （QCSE） electroabsorption in Ge quantum wells （QWs） with SiGe barriers grown on Si substrates. Though Ge is an indirect gap semiconductor, the resulting effects are at least as clear and strong as seen in typical III-V QW structures at similar wavelengths. We also demonstrated a modulator, with eye diagrams of up to 3.5 GHz, a small driving voltage of 2.5 V and a modulation bandwidth at about 10 GHz. Finally, carrier dynamics under ultra-fast laser excitation and high- speed photocurrent response are investigated.We focus on the optimization of SiGe material deposition, the minimization of the parasitic capacitance of the probe pads for high speed, low voltage and high contrast ratio operation. The device fabrication is based on processes for standard Si electronics and is suitable for mass-production. We present observations of quantum confinement and quantum-confined Stark effect （QCSE） electroabsorption in Ge quantum wells （QWs） with SiGe barriers grown on Si substrates. Though Ge is an indirect gap semiconductor, the resulting effects are at least as clear and strong as seen in typical III-V QW structures at similar wavelengths. We also demonstrated a modulator, with eye diagrams of up to 3.5 GHz, a small driving voltage of 2.5 V and a modulation bandwidth at about 10 GHz. Finally, carrier dynamics under ultra-fast laser excitation and high- speed photocurrent response are investigated.

关 键 词：electroabsorption effect Ge optical intercon-nections optical modulators quantum-confined Stark effect（QCSE） Ge/SiGe quantum wells （QWs） 

分 类 号：TN322.8[电子电信—物理电子学] O472[理学—半导体物理]