983 A terahertz-vibration to terahertz-radiation converter based on gold nanoobjects: a feasibility study Kamil Moldosanov *1 and Andrei Postnikov *2 Full Research Paper Open Access Address: 1 Kyrgyz-Russian Slavic University, 44 Kiyevskaya St., Bishkek 720000, Kyrgyzstan and 2 Université de Lorraine, Institut Jean Barriol, LCP-A2MC, 1 Bd Arago, F-57078 Metz, France Email: Kamil Moldosanov * - altair1964@yandex.ru; Andrei Postnikov * - andrei.postnikov@univ-lorraine.fr * Corresponding author Keywords: longitudinal acoustic phonon; microwave photon; nanobar; nanoring; terahertz emitter Beilstein J. Nanotechnol. 2016, 7, 983–989. doi:10.3762/bjnano.7.90 Received: 22 January 2016 Accepted: 21 June 2016 Published: 06 July 2016 This article is part of the Thematic Series "Physics, chemistry and biology of functional nanostructures III". Guest Editor: A. S. Sidorenko © 2016 Moldosanov and Postnikov; licensee Beilstein-Institut. License and terms: see end of document. Abstract Background: The need for practical and adaptable terahertz sources is apparent in the areas of application such as early cancer diagnostics, nondestructive inspection of pharmaceutical tablets, visualization of concealed objects. We outline the operation prin- ciple and suggest the design of a simple appliance for generating terahertz radiation by a system of nanoobjects – gold nanobars (GNBs) or nanorings (GNRs) – irradiated by microwaves. Results: Our estimations confirm a feasibility of the idea that GNBs and GNRs irradiated by microwaves could become terahertz emitters with photon energies within the full width at half maximum of the longitudinal acoustic phononic DOS of gold (ca. 16–19 meV, i.e., 3.9–4.6 THz). A scheme of the terahertz radiation source is suggested based on the domestic microwave oven irradiating a substrate with multiple deposited GNBs or GNRs. Conclusion: The size of a nanoobject for optimal conversion is estimated to be approx. 3 nm (thickness) by approx. 100 nm (length of GNB, or along the GNR). This detailed prediction is open to experimental verification. An impact is expected onto further studies of interplay between atomic vibrations and electromagnetic waves in nanoobjects. 983 Introduction The terahertz (THz) range of the electromagnetic waves, the range between microwaves and infrared (IR), is often discussed in reference to the “terahertz gap”, where “electronics meets optics”. The corresponding radiation, exhibiting properties common to one or the other of its neighbouring ranges, can be refracted and focused by lenses, like IR rays, and penetrate many optically opaque barriers, like microwaves. However, the methods of radiation generation and detection, elaborated for these adjacent ranges, are not efficient in the THz range and do face grave challenges. This hinders the creation of devices that