Era of THz technology and different techniques for generation and detection systems of THz-waves

Terahertz (THz) technology deals with a wide range of applications such as, astronomy, environmental sciences, biology, and spectroscopy. The relatively new technique of coherent electromagnetic radiation, in the region of THz, has potential to detect the nature of low energy processes in physics, chemistry and biomedicine. The paper describes the different methods of generation and detection of THz fields at these wavelengths. The paper also describes the most recent results in THz fields and is focused on the physical principles of terahertz-wave generators, especially optical parametric oscillators have been described in the last. The paper also provides some information about some detectors and mixers used in the detection systems for THz-waves detection.