1.3.3 Types Of Non-Ionizing Radiation
For the purposes of radiation safety, non-ionizing radiation is broken into a number of broad types:
- Electric and Magnetic Field (EMF): 0-100 kHz. Low-level electromagnetic radiation arising from the delivery of domestic electrical power across transmission lines and its distribution, as well as some workshop and laboratory equipment.
- RF radiation: 100 kHz to 300 GHz. Electromagnetic waves that do not ionize atoms or molecules. Its frequency range spans from very low frequencies to the visible spectrum.
- Infrared Radiation (IR): 300 GHz to 430 THz. Emitted by heat sources and used in remote controls and thermal imaging.
- Visible Light: 430 THz to 750 THz. The visible spectrum.
- Ultraviolet Radiation (UV): 750 THz to 30,000 THz (or 30 PHz). Approximately 400 nanometers (nm) down to 10 nanometers (nm). Commonly used in industrial curing, sterilization/disinfection, counterfeiting detection, and medical phototherapy. Extreme UV frequencies possess enough energy to ionize atoms.
- Lasers: 300 GHz to 30 EHz. Lasers are highly coherent and monochromatic light.
- Infrared (IR) Lasers: ~300 GHz - ~430 THz (700 nm to 1 mm). Examples: CO₂ (10.6 µm), Nd:YAG lasers (1064 nm), fiber lasers, and telecom lasers (1550 nm).
- Visible Light Lasers: ~430 to ~750 THz (400 nm to 700 nm). Examples: Helium-neon (633 nm), argon-ion (488 nm and 514 nm), and GaN diode lasers for blue, green and red light.
- Terahertz Lasers (Far Infrared): ~0.1 to ~10 THz (30 µm to 3 mm). Free-electron lasers (FELs) and quantum cascade lasers.
- Ultraviolet (UV) Lasers: ~750 THz to ~30 PHz (10 nm to 400 nm). Examples: Excimer lasers, frequency-doubled solid-state lasers (e.g., Nd:YAG at 355 nm.
- X-ray Lasers: ~30 PHz to ~30 EHz (0.01 nm to 10 nm). Examples: Free-electron X-ray lasers.
This book focuses on the safety aspects of RF radiation 100 kHz to 300 GHz.