Abstract

A material in the form of a multilayer structure based on low-temperature LT-GaAs grown on (111)A-oriented substrates is proposed for fabrication of THz photoconductive antennas. These structures contain active LT-GaAs layers and doping acceptor GaAs:Si-based layers. At the optical pump power of 19 mW and the bias voltage of 30 V, a photoconductive antenna based on the optimized {LT-GaAs/GaAs:Si} (111)A structure emits THz pulses with the average power of 2.3 μW at the pulse repetition frequency of 80 MHz; the conversion efficiency is 1.2 × 10^–4. It is shown that the dependence of the integral power of THz pulses of the antenna based on the {LT-GaAs/GaAs:Si} (111)A structure on the applied voltage is superlinear; the dependence of this parameter on the optical pump power is plotted as a curve with saturation. It is shown that the designed antennas have a practical application in THz spectroscopy of biological solutions.

中文翻译：

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基于{LT-GaAa / GaAa：Si}超晶格结构的光电导天线的太赫兹辐射

摘要

提出了一种基于在（111）A取向衬底上生长的低温LT-GaAs的多层结构形式的材料，用于制造THz光电导天线。这些结构包含有源LT-GaAs层和掺杂受体GaAs：Si基层。以优化的{LT-GaAs / GaAs：Si}（111）A结构为基础的光导天线在19 mW的光泵功率和30 V的偏置电压下发射的THz脉冲平均功率为2.3μW重复频率为80 MHz；转换效率为1.2×10 ^–4。结果表明，基于{LT-GaAs / GaAs：Si}（111）A结构的天线太赫兹脉冲积分功率对施加电压的依赖性是超线性的。该参数对光泵浦功率的依赖性绘制为饱和曲线。结果表明，所设计的天线在生物溶液的太赫兹光谱中具有实际应用。