Infrared radiation is a form of electromagnetic radiation with longer wavelengths than visible light. The exact range of wavelengths considered as infrared radiation can vary depending on the context and the source of information. However, the general range typically accepted for infrared radiation is from approximately 700 nanometers (nm) to 1 millimeter (mm).
To put it in perspective, the visible light spectrum ranges from approximately 400 nm (violet) to 700 nm (red). Infrared radiation extends beyond the red end of the visible spectrum, starting at around 700 nm and continuing to longer wavelengths. Within the infrared spectrum, there are typically three divisions:
Near-infrared (NIR): This region ranges from approximately 700 nm to 1,400 nm. Near-infrared radiation is often used in applications such as remote controls, fiber optic communications, and night vision technology.
Mid-infrared (MIR): The mid-infrared region ranges from approximately 1,400 nm to 10,000 nm (or 10 micrometers). This range is commonly used in spectroscopy, thermal imaging, and detecting heat signatures.
Far-infrared (FIR): The far-infrared region spans from approximately 10,000 nm (or 10 micrometers) to 1 mm. Far-infrared radiation is often associated with thermal radiation and is used in applications such as thermal imaging cameras and astronomy.
It's worth noting that the boundaries between these regions can vary slightly depending on the specific source and application. Nonetheless, infrared radiation as a whole encompasses a range of wavelengths longer than those of visible light.