The mathematics used in this chapter is limited to the operations of addition, subtraction, multiplication, division and a little differentiation.
In this chapter, we look at sensors of terahertz-frequency electromagnetic radiation. Terahertz sensors detect invisible terahertz radiation and convert it to something perceptible to a human being – usually a number on a dial or on a screen.
Terahertz-frequency electromagnetic radiation is invisible. The human eye cannot see it. How can we tell it is there?
The other human senses are not much help. We cannot taste, or hear, or smell terahertz radiation. We can feel it – we perceive terahertz radiation as heat – but only if it is rather intense. The human body, on the whole, is ...