We carried out an experimental comparison study of the two most established optoelectronic emitters for continuous-wave (cw) terahertz generation: a uni-traveling-carrier photodiode (UTC-PD) and a pin-photodiode (PIN-PD). Both diodes are commercially available and feature a similar package (fiber-pigtailed housings with a hyper-hemispherical silicon lens). We measured the terahertz output as a function of optical illumination power and bias voltage from 50 GHz up to 1 THz, using a precisely calibrated terahertz power detector. We found that both emitters were comparable in their spectral power under the operating conditions specified by the manufacturers. While the PIN-PD turned out to be more robust against varying operating parameters, the UTC-PD showed no saturation of the emitted terahertz power even for 50 mW optical input power. In addition, we compared the terahertz transmission and infrared (IR) blocking ratio of four different filter materials. These filters are a prerequisite for correct measurements of the absolute terahertz power with thermal detectors.

中文翻译：

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用于连续波太赫兹产生的UTC和PIN光电二极管的实验比较

我们对用于连续波（cw）太赫兹产生的两种最成熟的光电发射器进行了实验比较研究：单行进载流光电二极管（UTC-PD）和pin光电二极管（PIN-PD）。两种二极管都可以在市场上买到，并且具有相似的封装（带半球状硅透镜的光纤尾纤外壳）。我们使用精确校准的太赫兹功率检测器测量了太赫兹输出随光照明功率和偏置电压（从50 GHz到1 THz）变化的函数。我们发现，在制造商指定的工作条件下，两个发射器的频谱功率均相当。尽管PIN-PD可以抵抗各种工作参数，但更坚固，但UTC-PD即使在50 mW的光输入功率下，也不会出现太赫兹功率的饱和。此外，我们比较了四种不同滤光材料的太赫兹透射率和红外（IR）阻挡率。这些滤波器是使用热探测器正确测量绝对太赫兹功率的先决条件。