Abstract-Terahertz cascades from a nanoparticle

K.B. Arnardottir, T.C.H. Liew

(Submitted on 21 Mar 2017)

http://export.arxiv.org/abs/1703.07119

In this letter we propose a new system capable of THz radiation with quantum efficiency above unity. The system consists of nanoparticles where the material composition varies along the radial direction of each nanoparticle in such a way that a ladder of equidistant energy levels emerges. By then exciting the highest level of this ladder we produce multiple photons of the same frequency in the THz range.

Abstract-Development of Nanoparticle-Based High Current Density Cathode for THz Devices Application

R. K. Barik, A. K. Singh, S. Shukla, T. P. Singh, R. S. Raju, G. -S. Park,

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7415986&filter%3DAND%28p_IS_Number%3A4358746%29

Skandia (Sc₂O₃)-doped tungsten nanoparticle-based high current density cathode is developed for the application in terahertz (THz) devices. This paper involves synthesis of scandia-doped tungsten nanoparticle powder using chemical technique, estimation of optimum porosity, and development of pellet with required porosity by optimizing process parameters. The cathode, made out of the above pellet, is tested in an analytical system containing Auger electron spectroscope and anode. The results show that the cathode can deliver more than 100 A/cm² current density with stable emission--strongly recommending it as a candidate for the use in a THz device. Theoretical estimates show that the void porosity is to be kept at 21% for proper surface coverage to produce good emission with long life.