This paper presents an overview of THz-technologies, and especially their use for communications. Different approaches on the physics of THz radiation are discussed, from the Radio Frequency (RF) perspective, as well as from the Far Infrared (FIR) optic signals' perspective and Nano electronics' and molecular electronics' perspective. Experiments with THz Continuous Wave (CW) frequency domain spectroscopy are presented. The goal of the experiment was to determine a frequency band with constant received power, high Signal to Noise Ratio (SNR) and no water absorption lines near such potential frequency band. From spectroscopy experimental result suitable frequency bands with bandwidth of 20 GHz to 50 GHz were found, what promises the possibility of achieving high communication data rates in next few years of several hundred Gb/s over distances about 1 km using THz waves. So, the relations between transmission media spectroscopy measurements and channel amplitude frequency characteristic was shown. From the instrumentation description it is also evident that, the experimental platform used is suitable for research and, as well for the education purpose, in communications', sensors', and materials' courses and related curses.
COBISS.SI-ID: 23031830
Terahertz spectrometry offers new opportunities in material research, mostly because THz waves are non-destructive towards biological material and opaque materials. Technology is still not widely available, but there is high demand for it. There are three main methods of generating THz waves. Most promising and not yet fully developed is opto-electrical method, which is presented in this paper. A demonstration of sample measurements is also presented.
COBISS.SI-ID: 23030806
Chemical analysis is widely used in different fields. It is based on spectroscopy and different methods. One of the upcoming technology is terahertz (THz) spectroscopy, but it is not yet well researched. This paper presents opto-electrical methods for generating THz waves and it presents frequency-domain spectroscopy as the possible solution to problems, that are presented in infrared, visible-light, ultraviolet, x-ray and gamma spectroscopies. Basic analysis techniques are presented, including deriving absorption coefficient and refractive index. Both are interconnected with Kramer-Kronig relation and are fundamental sample characteristics that can be measured with spectrometers. Example of measuring transmittance and refractive index are presented in experiment, made with frequency-domain spectroscopy platform TeraScan 1550.
COBISS.SI-ID: 23030550