Infrared wavelengths are a portion of the electromagnetic spectrum with wavelengths longer than visible red light, ranging from 780 nanometers (nm) to 1 millimeter (mm).
Understanding Infrared Radiation
Infrared (IR) radiation, often referred to as thermal radiation, sits between visible light and microwaves in the electromagnetic spectrum. It's a type of electromagnetic radiation that we experience as heat.
Infrared Wavelength Subdivisions
For better understanding and specific applications, infrared radiation is typically divided into three regions:
- Near-Infrared (IR-A): 780 nm - 1.4 µm
- Mid-Infrared (IR-B): 1.4 µm - 3 µm
- Far-Infrared (IR-C): 3 µm - 1 mm
These sub-categories are useful because different materials interact differently with each range, and different technologies can be best suited for generating or detecting specific ranges.
Key Characteristics
- Invisible to the Human Eye: Although we can't see infrared radiation, we can feel it as heat.
- Thermal Radiation: Objects emit infrared radiation based on their temperature; hotter objects emit more.
- Diverse Applications: Infrared technology is used in a wide variety of fields, including:
- Remote controls
- Thermal imaging
- Fiber optic communication
- Medical diagnostics
- Industrial heating
- Scientific Research
Sources of Infrared Radiation
Infrared radiation is emitted by a variety of sources:
- The Sun: A significant portion of the sun's energy reaches Earth as infrared radiation.
- Heat Lamps: Designed to emit infrared radiation for warming.
- Humans and Animals: Emit infrared radiation as heat.
- Incandescent Bulbs: Emit a significant amount of energy as heat (infrared radiation).
- Specialized Infrared Emitters (LEDs, Lasers): Used in various technologies.
In summary, infrared wavelengths are part of the electromagnetic spectrum with wavelengths longer than visible red light, spanning from 780 nm to 1 mm, and are further subdivided into near, mid, and far-infrared regions, each with unique characteristics and applications.
