Published in Opto-Electronics Review
We consider new concepts of terahertz and infrared photodetectors based on multiple graphene layer and multiple graphene nanoribbon structures and we evaluate their responsivity and detectivity. The performance of the detectors under consideration is compared with that of photodetectors made of the traditional structures. We show that due to high v...
Published in Chinese Science Bulletin
Gyrotrons are high powered coherent electromagnetic radiation sources, and are considered to be available powerful sources that have the potential to bridge the so-called terahertz gap. In the University of Electronic Science and Technology of China, a second harmonic gyrotron has been designed, manufactured, and tested. The gyrotron generated radi...
A 2 x 2 array of 280-GHz Schottky-barrier diode detectors with an on-chip patch antenna (255 x 250 mu m(2)) is fabricated in a 130-nm logic CMOS process. The series resistance of diode is minimized using poly-gate separation (PGS), and exhibits a cut-off frequency of 2 THz. Each detector unit can detect an incident carrier with 100-Hz similar to 2-...
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Published in Chinese Science Bulletin
By numerically solving Maxwell’s equations and rate equations in a two-dimensional (2D) active random media made of ruby grains with a three-level atomic system, the threshold gain behavior for a THz random laser is investigated. The spectral intensity variation with the pumping rate is calculated for both the transverse magnetic (TM) field and the...
Published in Journal of Applied Spectroscopy
Terahertz time-domain spectroscopy (THz-TDS) was employed to record the progress of the reaction between p-benzoquinone (BQ) and 4,4′-biphenol (4BP) in the solid state. Through the THz-TDS, distinct absorption peaks of reactants and products were obtained. Sample preparations in the solid state, with and without grinding, influenced the conversion ...
The study of photovoltaic materials is important so as to develop new solar energy technologies: in particular, quantum-confined semiconductors could offer increased quantum efficiencies at a much lower manufacture cost. This thesis contains results from a number of pump-probe experiments designed to probe the carrier dynamics in bulk and quantum-c...
Published in Sensors (Basel, Switzerland)
The terahertz (THz) spectral region, covering frequencies from 1 to 10 THz, is highly interesting for chemical sensing. The energy of rotational and vibrational transitions of molecules lies within this frequency range. Therefore, chemical fingerprints can be derived, allowing for a simple detection scheme. Here, we present an optical sensor based ...
Ce travail présente une étude de lasers à cascade quantique à l'aide de la spectroscopie THz dans le domaine temporel. Cette technique expérimentale consiste en la mesure de champs électriques THz transmis par un échantillon, permettant d'étudier des effets à la fois statiques et dynamiques dans les semiconducteurs. Les lasers à cascade quantique T...
Sigillography is the science that studies the manifold aspects of the seals. A seal can be defined as an imprint obtained on a malleable medium by imprinting an incised matrix, which transfers on it the characteristic signs of a person or an institution. We use THz spectroscopy and imaging for non-destructive evaluation of natural materials within ...
