We have developed a broadband and high-precision terahertz (THz) frequency counter based on a semiconductor-superlattice harmonic mixer (SLHM). Comparison of two THz frequencies determined using two independent counters and direct measurement of frequency-stabilized THz-quantum cascade lasers by a single counter showed a measurement uncertainty of less than 1 10⁻¹⁶ over a four-octave range from 120 GHz to 2.8 THz. Further extension of this measurable range was indicated by the research regarding the higher-harmonics generation of a local oscillator for the SLHM. This compact and easy-to-handle THz counter operating at room temperature is available for high-resolution spectroscopy of ultracold molecules proposed for detecting temporal changes in physics constants as well as many THz applications requiring a wide measurement range without a bulky cryogenic apparatus.

我们开发了一种基于半导体超晶格谐波混频器 (SLHM) 的宽带高精度太赫兹 (THz) 频率计数器。使用两个独立计数器确定的两个太赫兹频率的比较和由单个计数器直接测量频率稳定的太赫兹量子级联激光器显示测量不确定度小于 1 10 ^-16在 120 GHz 至 2.8 THz 的四个倍频程范围内。有关 SLHM 的本地振荡器的高次谐波生成的研究表明该可测量范围的进一步扩展。这种在室温下运行的紧凑且易于操作的太赫兹计数器可用于超冷分子的高分辨率光谱学，用于检测物理常数的时间变化以及许多需要宽测量范围的太赫兹应用，而无需笨重的低温设备。