中国物理B ›› 2009, Vol. 18 ›› Issue (12): 5534-5538.doi: 10.1088/1674-1056/18/12/067

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Intraband dynamics and terahertz emission in biased semiconductor superlattices coupled to double far-infrared pulses

李敏, 米贤武   

  1. College of Physics Science and Information Engineering, Jishou University, Jishou 416000, China
  • 收稿日期:2009-03-09 修回日期:2009-07-06 出版日期:2009-12-20 发布日期:2009-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10647132) and the Scientific Research Fund of Hunan Provincial Education Department of China (Grant No 05B014).

Intraband dynamics and terahertz emission in biased semiconductor superlattices coupled to double far-infrared pulses

Li Min(李敏) and Mi Xian-Wu(米贤武)†   

  1. College of Physics Science and Information Engineering, Jishou University, Jishou 416000, China
  • Received:2009-03-09 Revised:2009-07-06 Online:2009-12-20 Published:2009-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10647132) and the Scientific Research Fund of Hunan Provincial Education Department of China (Grant No 05B014).

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摘要： This paper studies both the intraband polarization and terahertz emission of a semiconductor superlattice in combined dc and ac electric fields by using the superposition of two identical time delayed and phase shifted optical pulses. By adjusting the delay between these two optical pulses, our results show that the intraband polarization is sensitive to the time delay. The peak values appear again for the terahertz emission intensity due to the superposition of two optical pulses. The emission lines of terahertz blueshift and redshift in different ac electric fields and dynamic localization appears. The emission lines of THz only appear to blueshift when the biased superlattice is driven by a single optical pulse. Due to excitonic dynamic localization, the terahertz emission intensity decays with time in different dc and ac electric fields. These are features of this superlattice which distinguish it from a superlattice generated by a single optical pulse to drive it.

Abstract: This paper studies both the intraband polarization and terahertz emission of a semiconductor superlattice in combined dc and ac electric fields by using the superposition of two identical time delayed and phase shifted optical pulses. By adjusting the delay between these two optical pulses, our results show that the intraband polarization is sensitive to the time delay. The peak values appear again for the terahertz emission intensity due to the superposition of two optical pulses. The emission lines of terahertz blueshift and redshift in different ac electric fields and dynamic localization appears. The emission lines of THz only appear to blueshift when the biased superlattice is driven by a single optical pulse. Due to excitonic dynamic localization, the terahertz emission intensity decays with time in different dc and ac electric fields. These are features of this superlattice which distinguish it from a superlattice generated by a single optical pulse to drive it.

Key words: density matrix theory, semiconductor superlattice, terahertz emission

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

  • 78.70.Gq
68.65.Cd (Superlattices) 71.35.-y (Excitons and related phenomena) 73.21.Cd (Superlattices)