We present photomixers made of iron doped indium gallium arsenide (InGaAs:Fe) as broadband receivers in optoelectronic continuous wave (cw) terahertz (THz) systems. InGaAs:Fe shows higher resistivity and shorter carrier lifetimes compared to the state-of-the-art low-temperature-grown material. These improved material properties translate into an improved frequency response and lower noise level of the InGaAs:Fe photomixers. We were able to measure a bandwidth of 4.5 THz with a peak dynamic range of 112 dB at 30 mW laser excitation around 1550 nm. To the best of our knowledge, these are record high values for cw THz spectroscopy. Furthermore we achieved an increased dynamic range by up to 10 dB for frequencies above 1 THz compared to state-of-the-art photomixing receivers. These improvements enable faster and more precise spectroscopy with higher bandwidth. In industrial non-destructive testing, the measurement rate may be increased by a factor of ten posing a valuable contribution to inline process monitoring.

中文翻译：

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具有 4.5 THz 带宽和 112 dB 动态范围的连续波太赫兹接收器

我们提出了由掺铁铟镓砷 (InGaAs:Fe) 制成的光混合器，作为光电连续波 (cw) 太赫兹 (THz) 系统中的宽带接收器。与最先进的低温生长材料相比，InGaAs:Fe 显示出更高的电阻率和更短的载流子寿命。这些改进的材料特性转化为 InGaAs:Fe 光混合器的改进频率响应和更低的噪声水平。我们能够在 1550 nm 附近的 30 mW 激光激发下测量 4.5 THz 的带宽，峰值动态范围为 112 dB。据我们所知，这些是连续太赫兹光谱的创纪录高值。此外，与最先进的光混合接收器相比，对于 1 THz 以上的频率，我们实现了高达 10 dB 的动态范围增加。这些改进可实现更快、更精确的光谱分析和更高的带宽。在工业无损检测中，测量速率可以提高 10 倍，这对在线过程监控做出了宝贵贡献。