Application Of Terahertz Electromagnetic Waves in The Field of Detection

Abstract

Among all kinds of electromagnetic waves, terahertz (THz) waves are those with frequencies varying from 0.1 to 10 THz (with wavelengths ranging from 3000 to 30x10-6 m). Millimeter waves in the long wavelength range overlap with electromagnetic waves, as well as infrared light in the short wavelength range. The THz gap in the electromagnetic spectrum is the crossover between electronics and photonics, and between macroscopic classical theory and microscopic quantum theory. The THz wave band has the same characters as spectrum of substances such as semiconductors, plasmas, organisms, and biomolecules, having the characteristics of quantum energy and low blackbody temperature. The time-domain spectral signal-to-noise ratio of THz is very high, making it excellent for applications involving images. Because of the extremely large instantaneous bandwidth (0.1-10THz), high-speed transmission is possible. Therefore, utilizing THz can deepen and broaden humans’ knowledge of some fundamental scientific issues in physics, chemistry, astronomy, informatics, and life sciences. At present, technology related to THz wave is widely used in temperature sensors, biosensors, communication, astronomy, and safety inspection fields.