ABSTRACT
The sixth generation (6G) high-speed and higher frequency spectrum is on demand for nano-communication (NC). By using the terahertz (THz) frequency, it is becoming an interesting field for recent researchers which can be useful for many sensitive applications like spectroscopy, imaging, detecting, tracking, sensing, and so forth. In NC, THz radiation has enormous potential in medical applications as within it lie the frequencies of certain elementary excitations of semiconductors and dielectrics, vibrational and rotational spectra of polymers and biological molecules, including drugs and explosives. This allows the use of THz radiation for the diagnosis of diseases, quality control of food and drugs, the detection of biological and chemical agents. With the current advancement of nanotechnology and material research, the advent of photoconductive antenna (PCA) put the search on hold for portable, cost-effective, efficient, high-power pulsed THz sources and detector. A suitable nano structured PCA, pumped by portable ultrafast fiber laser, can generate, and detect THz pulses. This is essential for diverse medical applications including cancer detection, skin cancer, wound and burn inspection, dental imaging, THz endoscopy, and so forth. In this chapter, THz generation and detection using various methods, starting from electrical, optical, and electro-optic methods has been described. However, the focus is given to PCA as it is the best possible way for THz generation and detection. For PCA, the classifications, equivalent circuital analysis, numerical simulations, and experimental characterization has been reported in detail.
