中国物理B ›› 2009, Vol. 18 ›› Issue (12): 5518-5522.doi: 10.1088/1674-1056/18/12/065

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Anomalous behaviours of terahertz reflected waves transmitted from GaAs induced by optical pumping

施宇蕾, 周庆莉, 赵冬梅, 张存林   

  1. Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing \rm 100048, China
  • 收稿日期:2009-07-10 修回日期:2009-08-26 出版日期:2009-12-20 发布日期:2009-12-20
  • 基金资助:
    Project supported by the National Basic Research Program of China (973 Program) (Grant Nos 2007CB310408 and 2006CB302901), the National Natural Science Foundation of China (Grant No 10804077), Science Foundation of Beijing Municipal Commission of Educatio

Anomalous behaviours of terahertz reflected waves transmitted from GaAs induced by optical pumping

Shi Yu-Lei(施宇蕾),Zhou Qing-Li(周庆莉)†, Zhao Dong-Mei(赵冬梅), and Zhang Cun-Lin(张存林)   

  1. Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048, China
  • Received:2009-07-10 Revised:2009-08-26 Online:2009-12-20 Published:2009-12-20
  • Supported by:
    Project supported by the National Basic Research Program of China (973 Program) (Grant Nos 2007CB310408 and 2006CB302901), the National Natural Science Foundation of China (Grant No 10804077), Science Foundation of Beijing Municipal Commission of Educatio

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摘要： Femtosecond pump-terahertz probe studies of carrier dynamics in semi-insulating GaAs have been investigated in detail for various pump powers. It is observed that, at high pump powers, the reflection peaks flip to the opposite polarity and dramatically enhance as the pump arrival time approaches the reflected wave of the terahertz pulse. The abnormal polarity-flip and enhancement can be interpreted by the pump-induced enhancement in the photoconductivity of GaAs and half-wave loss. Moreover, the carrier relaxation processes and surface states filling in GaAs are also studied in these measurements.

Abstract: Femtosecond pump-terahertz probe studies of carrier dynamics in semi-insulating GaAs have been investigated in detail for various pump powers. It is observed that, at high pump powers, the reflection peaks flip to the opposite polarity and dramatically enhance as the pump arrival time approaches the reflected wave of the terahertz pulse. The abnormal polarity-flip and enhancement can be interpreted by the pump-induced enhancement in the photoconductivity of GaAs and half-wave loss. Moreover, the carrier relaxation processes and surface states filling in GaAs are also studied in these measurements.

Key words: terahertz, carrier dynamics, reflected wave

中图分类号:  (Microwave and radio-frequency interactions)

  • 78.70.Gq
72.20.Fr (Low-field transport and mobility; piezoresistance) 72.40.+w (Photoconduction and photovoltaic effects) 72.80.Ey (III-V and II-VI semiconductors) 73.20.At (Surface states, band structure, electron density of states)