THz emission from quantum dot-based THz antennas pumped by a tunable quantum-dot laser diode
THz emission from quantum dot-based THz antennas pumped by a tunable quantum-dot laser diode
复制标题
由可调谐量子点激光二极管泵浦的基于量子点的太赫兹天线的太赫兹发射
DOI：
10.1109/cleoe-iqec.2013.6800814
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
E. Rafailov
中科院分区：
文献类型：
--
作者：
R. Leyman;D. Carnegie;K. Fedorova;N. Bazieva;S. Schulz;C. Reardon;E. Clarke;E. Rafailov
太赫兹光电子学领域现在正在成熟，并且基于晶闸管的太赫兹天线设备正变得越来越广泛地实施为光谱学和成像中的分析工具。光导（PC）THz开关/天线通常使用超短脉冲激光或由两个同时的纵向波长组成的光信号来光学驱动，所述两个同时的纵向波长在PC材料中以THz差频一起拍频。这允许产生（光）载流子对，然后通常通过贯穿活性材料晶格的缺陷和捕获位点在超短时间尺度上捕获载流子对。通常使用具有相对高的带隙能量的缺陷注入的PC材料，并且诸如载流子迁移率和PC增益的许多参数被极大地损害。本文演示了嵌入标准晶体GaAs中的低带隙能量InAs量子点（QD）作为PC介质和PC THz天线中的超快捕获机制的实现。这种半导体结构是使用标准MBE方法生长的，并允许该器件在高达~1.3 μm的波长下被有效地光学驱动，在这种情况下，由单个可调谐双模QD二极管激光器驱动。
The THz optoelectronics field is now maturing and semiconductor-based THz antenna devices are becoming more widely implemented as analytical tools in spectroscopy and imaging. Photoconductive (PC) THz switches/antennas are driven optically typically using either an ultrashort-pulse laser or an optical signal composed of two simultaneous longitudinal wavelengths which are beat together in the PC material at a THz difference frequency. This allows the generation of (photo)carrier pairs which are then captured over ultrashort timescales usually by defects and trapping sites throughout the active material lattice. Defect-implanted PC materials with relatively high bandgap energy are typically used and many parameters such as carrier mobility and PC gain are greatly compromised. This paper demonstrates the implementation of low bandgap energy InAs quantum dots (QDs) embedded in standard crystalline GaAs as both the PC medium and the ultrafast capture mechanism in a PC THz antenna. This semiconductor structure is grown using standard MBE methods and allows the device to be optically driven efficiently at wavelengths up to ~1.3 μm, in this case by a single tunable dual-mode QD diode laser.