Terahertz imaging explained

摘要

Over the past several decades, imaging technology has become increasingly prevalent in our society. From the x-ray scanners we routinely encounter at the airport, to the ultrasound scanners that provide vivid pictures of babies in the womb and magnetic resonance imaging (MRI) machines that illustrate the organs inside the body with immense detail, imaging technology makes direct contributions to our security and health on a regular basis. The benefits brought about by this technology are all due to the efforts of physicists, engineers, and clinicians to understand and manipulate some of the most basic concepts governing the interaction of electromagnetic radiation with matter. For example, x-rays used in diagnostic radiology interact with tissue primarily via Compton scattering and photoelectric absorption, whereas MRI exploits proton spin density and relaxation mechanisms to produce exquisite medical images.