A5044127831- Superconducting and THz Device Technology
- Terahertz technology and applications
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Metamaterials and Metasurfaces Applications
- Energy Harvesting in Wireless Networks
- Spectroscopy and Laser Applications
- Millimeter-Wave Propagation and Modeling
- Antenna Design and Analysis
Nanjing University
2014-2020
We demonstrate an electrically tunable superconducting metamaterial capable of modulating terahertz waves dynamically. The device is based on electromagnetically induced transparency-like metamaterials, and the maximum modulation depth reaches 79.8% in transmission window. Controlled by electrical sinusoidal signal, such a could achieve speed approximately 1 MHz. superior property simplicity design make this promising for development high performance THz systems.
With the emergence and development of artificially structured electromagnetic materials, active terahertz (THz) metamaterial devices have attracted significant attention in recent years. Tunability transmission is desirable for many applications. For example, short-range wireless THz communications ultrafast interconnects require switches modulators. However, tunable range amplitude existing not satisfactory. In this article, we experimentally demonstrate an electrically superconducting...
Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) and biased by a simple microwave (MW) source have been studied. The frequency power of the MW are selected measuring responses current–voltage (I–V) curves resistance–temperature (R–T) NbN HEBs. non-uniform absorption theory is used to explain current jumps in I–V resistance R–T curves. Compared thermal biasing, biasing method can improve sensitivity, make readout system much easier...
We report on terahertz (THz) detectors with a high performance at room temperature using EuBiTe 3 crystals as the active material under mechanisms of bolometric and photothermoelectric effects (PTE). Our have simple structure can achieve sensitivity, even without coupling antenna optimization thermal environment. Under bias conditions, our results suggest that responsivities photodetector 1.84, 2.52, 3.11 THz are 0.35, 0.88 1.32 A/W in air, noise-equivalent power (NEP) 43.6, 16.4, 10.9 nW/Hz...
Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) with microwave (MW) biasing are studied. The MW is used to bias the HEB optimum point and readout impedance changes caused by incident THz signals. Compared thermal method, this method would be more promising in large scale array simple readout. NbN has an excellent performance as heterodyne detector double sideband noise temperature (TN) of 403 K working at 4.2 0.65 THz. As a...
In a quasi-optical system, the high temperature superconducting terahertz detector often suffers from fundamental problem of low coupling efficiency with signal, especially for based on YBa 2 Cu 3 O 7- δ (YBCO) bicrystal Josephson junction (JJ) due to small normal-state resistance. Here, we developed bowtie loaded meander antenna enhance efficiency. Differing conventional characterization confining vector network analyzers, applied three methods evaluate antenna, including measurements...
Superconducting niobium nitride (NbN) hot electron bolometer (HEB) detectors consist of a complementary logarithmic-spiral antenna made gold and an NbN film (bridge) connecting across the antenna's inner terminals have been fabricated characterized. For its performance as heterodyne mixer, system DSB noise temperature about 500 K intermediate frequency (IF) gain bandwidth (GBW) 4 GHz obtained at 4.2 0.65 THz. direct detector, microwave-driven scheme has tried.
Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) with microwave (MW) injection have been studied. Compared to the thermal biasing method, injected MW is used here bias HEB optimum point. can be expected as easy read out for detecting array. The NbN has an excellent performance heterodyne detector noise temperature of 403 K working at 4.2 and 0.65 THz. As result, equivalent power (NEP) 1.4 pW/Hz <sup...
Intermediate frequency (IF) gain bandwidth (GBW) of terahertz (THz) mixers based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) has been improved. The IF GBW measured by 2 different methods and same values up to 7 GHz have obtained.
A system to detect the terahertz (THz) pulse signals has been studied based on superconducting NbN hot electron bolometer (HEB) detectors, which noise equivalent power (NEP) of 9×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> W/√Hz, together with a Fourier transform spectrometer (FTS). The detector driven by an easily adjustable microwave source its best bias working point, and output shown linear relationship incident THz power....
Superconducting niobium nitride (NbN) hot electron bolometers (HEBs) have been used widely in the astronomical observations with its low noise temperature [1] (a few times of quantum limit) as heterodyne detectors. On other hand, high coefficient resistance (TCR) and characteristics, NbN HEB can be considered direct Combined material's quick response property (response time:~ps), detector terahertz (THz) imaging weak THz ultrashort pulse signal detection. A system similar to microwave...