We studied and improved the performance of a terahertz (THz) direct detector based on the superconducting NbN hot electron bolometer (HEB) integrated with microwave readout for imaging arrays and other applications. A 6 nm thick NbN microbridge at the feed point of a twin-slot antenna is embedded into a high-Q quarter-wavelength coplanar waveguide (CPW) resonator made from a 350 nm thick NbN film which is weakly coupled to a CPW feedline. THz direct detection was performed at a signal frequency of 0.66 THz at a bath temperature of 4.2 K. When operating at a low input microwave power level, the device acting as a microwave kinetic inductance detector with a kinetic inductance fraction of 0.45 changes the surface impedance of the resonator in response to incident THz radiation. The estimated optical noise equivalent power (NEP) is ∼0.23 pW Hz^−0.5 which shows about one order of magnitude improvement compared to that of the traditional voltage-biased NbN HEBs. The improved performance of the THz direct detectors with lower NEP and easy readout makes them promising in imaging with a large number of the array pixels.

我们研究并改进了基于超导 NbN 热电子辐射热计 (HEB) 的太赫兹 (THz) 直接探测器的性能，该探测器与微波读数集成，用于成像阵列和其他应用。双槽天线馈电点处的 6 nm 厚 NbN 微桥嵌入到高Q四分之一波长共面波导 (CPW) 谐振器由 350 nm 厚的 NbN 薄膜制成，该薄膜弱耦合到 CPW 馈线。THz 直接检测是在 0.66 THz 的信号频率和 4.2 K 的浴温下进行的。当在低输入微波功率水平下运行时，该装置用作具有 0.45 动态电感分数的微波动态电感检测器，改变了表面阻抗谐振器响应入射太赫兹辐射。估计的光学噪声等效功率 ( NEP ) 为 ~0.23 pW Hz ^-0.5，与传统的电压偏置 NbN HEB 相比，这显示出大约一个数量级的改进。具有较低NEP的 THz 直接检测器的改进性能 易于读出使它们在具有大量阵列像素的成像中很有前景。