Technological advances in THz range and detection of thermal and non-thermal radiation

Abstract

The experimental advances in the spectral range between the visible and microwaves, known as THz region, have demonstrated their importance in several areas, from biomedical, sensing of materials, nanotechnology to space sciences, it also include revolutionary applications in medicine and security. Despite the various products developed the access to the instruments, subsystems and to the information are very restricted, mainly for countries as Brazil, becoming monopoly of few countries only. Military applications had acquired special importance. Most of photometric devices sales in 10 µm band directed for such applications, adding more difficulties to acquire information on new developments. Works carried out at the Center of Component Semiconductors (CCS – UNICAMP) had the objective to manufacture and to test subsystems necessary for THz photometry and imaging. The excellent results obtained indicate the need of additional developments and their optimization, with applications in projects which require photometry and imaging. On the other hand, in recent years the THz technology has been directed for the production of extreme-intense sources of coherent synchrotron radiation (in laboratory) as well as to its diagnosis, in this same spectral band. The photometry and imaging are essential for the best understanding of production processes of these radiations produced by electron beams of high energy, from laboratory scales to spatial scales. The developments and studies presented here will contribute for two space experiments recently proposed, DESIR (Solar Detection of eruptive Infrared Radiation) and SIRA (Submillimeter-wave to Solar InfraRed Activity emissions), requiring the use of THz systems for observations of transients in solar active plasmas at different frequencies, from the ground and from space. The knowledge already acquired and the developments considered here are intend to contribute for the characterization and qualification of devices and subsystems for THz photometry and imaging. Unique results are expected from its application for the diagnosis of particle acceleration mechanisms through their electromagnetic emissions in the THz band, mainly in solar hot plasmas, with important consequences for their interpretation, suggested as similar to equivalent processes in laboratory particle beam accelerators.