Terahertz nonlinear detection and quantum optical studies by resonant two-photon transitions in semiconductor quantum wells

半导体量子阱中共振双光子跃迁的太赫兹非线性检测和量子光学研究

• 批准号: 171331903
• 负责人: Privatdozent Dr. Harald Schneider
• 金额: --
• 依托单位: Institut für Ionenstrahlphysik und Materialforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/171331903?language=en
• 关键词: Terahertz; nonlinear; detection; quantum; optical

The aim of this project is exploiting two-photon transitions for nonlinear optical spectroscopy in the Terahertz(THz) regime, and to study second-order coherence and nonlinear susceptibility at frequencies in the range 1 – 7 THz. Our approach makes use of resonant two-photon absorption involving three energetically equidistant conduction subbands in GaAs/AlGaAs quantum wells. This optical nonlinearity is by six orders of magnitude more efficient as compared to bulk crystals and allows us to realize extremely sensitive quadratic detectors, suitable for autocorrelating extremely weak THz pulses. These detectors will be used for autocorrelation studies of photoconductive THz emitters pumped by femtosecond Ti: Sapphire lasers, and for quantum optical investigations of photon bunching of incoherent THz radiation from synchrotron-pumped infrared beamlines. The ultrashort correlation time of these radiation sources will allow us to determine intrinsic time constants of the detectors, thus gaining new information on intersubband dynamics, in particular on relaxation and dephasing well below the optical phonon frequencies. Another goal will be the study of phonon-polariton resonances of the nonlinear susceptibility in III-V semiconductors.

该项目的目的是利用太赫兹（THz）区域的非线性光谱学的双光子跃迁，并研究1 - 7太赫兹频率范围内的二阶相干性和非线性磁化率。我们的方法利用了GaAs/AlGaAs量子阱中涉及三个能量等距传导子带的共振双光子吸收。与体晶体相比，这种光学非线性的效率提高了6个数量级，使我们能够实现极其灵敏的二次型探测器，适用于自相关的极弱太赫兹脉冲。这些探测器将用于飞秒钛蓝宝石激光器泵浦的光导太赫兹发射器的自相关研究，以及同步加速器泵浦红外光束线非相干太赫兹辐射光子束的量子光学研究。这些辐射源的超短相关时间将使我们能够确定探测器的固有时间常数，从而获得关于子带间动力学的新信息，特别是关于远低于光学声子频率的弛豫和消相。另一个目标将是研究III-V半导体中非线性磁化率的声子-极化子共振。

项目成果

Magnetic control of Coulomb scattering and terahertz transitions among excitons

• DOI: 10.1103/physrevb.89.125313
• 发表时间: 2013-09
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: J. Bhattacharyya;S. Zybell;F. Esser;M. Helm;H. Schneider;L. Schneebeli;C. N. Bottge;B. Breddermann;M. Kira;S. Koch;A. Andrews;G. Strasser

Two-photon quantum well infrared photodetectors below 6 THz

• DOI: 10.1016/j.infrared.2014.08.012
• 发表时间: 2015-05
• 期刊: Infrared Physics & Technology
• 影响因子: 3.3
• 作者: C. Franke;M. Walther;M. Helm;H. Schneider