What is the frequency range of IR waves?

The frequency range of infrared (IR) waves is generally classified within 300 gigahertz (GHz) to 400 terahertz (THz). This classification is based on the electromagnetic spectrum, where infrared radiation falls just below the visible light spectrum.

In this range, IR waves are significant for several applications, including thermal imaging, remote sensing, and fiber optic communications. The wavelengths of IR waves correspond to higher frequencies compared to microwaves but lower than those of visible light, allowing them to interact with molecules in unique ways. The information pertaining to the physical properties of materials and their temperatures can be inferred from IR radiation, making this frequency range essential in various fields.

The references to other frequency ranges in the other choices, while they may correspond to other forms of electromagnetic radiation, do not appropriately capture the accepted boundaries for infrared waves in scientific literature. Thus, the selection of the range of 300 GHz to 400 THz is both accurate and in alignment with established definitions in physics and engineering contexts.