# Electromagnetic spectrum

The electromagnetic spectrum - EM spectrum for short and more precisely called the electromagnetic wave spectrum - is the entirety of all electromagnetic waves of different wavelengths . The light spectrum , also color spectrum , is the part of the electromagnetic spectrum that is visible to humans.

The spectrum is divided into different areas. This classification is arbitrary and, for historical reasons, is based on the wavelength in the low-energy range. Wavelength ranges over several orders of magnitude with similar properties are grouped into categories such as light , radio waves , etc. A subdivision can also be made according to the frequency or the energy of the individual photon (see below). In the case of very short wavelengths, correspondingly high quantum energy, a classification according to energy is common.

Arranged according to decreasing frequency and thus increasing wavelength, the short-wave and therefore high-energy gamma rays are located at the beginning of the spectrum , the wavelength of which extends into atomic orders of magnitude. At the end there are the longest waves , the wavelengths of which are many kilometers.

The wavelength is converted into a frequency using the formula . Where is the speed of light . ${\ displaystyle f}$${\ displaystyle f = c / \ lambda}$${\ displaystyle c}$

## The areas of the electromagnetic spectrum

Overview of the electromagnetic spectrum
Designation of
the
frequency range
Sub-designation wavelength frequency Photons -
energy
Generation / excitation Technical commitment
from to from to
Low frequency Extremely Low Frequency (ELF) 10 mm 100 mm 3 Hz 30 Hz > 2.0 · 10 −33  J
> 12 feV
Floor dipole , antenna systems Traction current
Super Low Frequency (SLF) 1 mm 10 mm 30 Hz 300 Hz > 2.0 · 10 −32  J
> 120 feV
Mains frequency , (formerly) submarine communication
Ultra Low Frequency (ULF) 100 km 1000 km 300 Hz
0.3 kHz
3000 Hz
3 kHz
> 2.0 · 10 −31  J
> 1.2 peV
Very Low Frequency (VLF)
Myriameter
waves Longitudinal waves (SLW)
10 km 100 km 3 kHz 30 kHz > 2.0 · 10 −30  J
> 12 peV
Submarine communication ( DHO38 , ZEVS , Sanguine , SAQ ), radio navigation , heart rate monitors
Radio waves Long wave (LW) 1 km 10 km 30 kHz 300 kHz > 2.0 · 10 −29  J
> 120 peV
Oscillator circuit + antenna Long wave radio , DCF77 , induction hob
Medium wave (MW) 100 m 1000 m 300 kHz 3 MHz > 2 · 10 −28  J
> 1.2 neV
Medium wave broadcasting , HF surgery , (1.7 MHz-3 MHz boundary wave , short wave broadcasting )
Short wave (KW) 10 m 100 m 3 MHz 30 MHz > 1.1 · 10 −27  J
> 12 neV
Boundary wave , shortwave broadcasting , HAARP , diathermy , RC model making
Ultra short wave (VHF) 1 m 10 m 30 MHz 300 MHz > 2.0 · 10 −26  J
> 120 neV
Oscillator circuit + antenna Radio , television , radar , magnetic resonance imaging
Microwaves Decimeter waves 10 centimeters  1 m 300 MHz 3 GHz > 2.0 · 10 −25  J
> 1.2 µeV
Magnetron , klystron , burl , cosmic background radiation

Excitation of nuclear magnetic resonance and electron spin resonance , molecular rotations

Radar , magnetic resonance imaging , cellular communications , television , microwave oven , WiFi , Bluetooth , GPS , 5G
Centimeter waves 1 cm  10 centimeters 3 GHz 30 GHz > 2.0 · 10 −24  J
> 12 µeV
Millimeter waves 1 mm 1 cm 30 GHz 300 GHz
0.3 THz
> 2.0 · 10 −23  J
> 120 µeV
Terahertz radiation 30 µm 3 mm 0.1 THz 10 THz > 6.6 · 10 −23  J
> 0.4 meV
Synchrotron , free-electron laser Radio astronomy , spectroscopy , imaging techniques
Infrared radiation (heat radiation) Far infrared 50 µm 1 mm 300 GHz 6 THz > 2.0 · 10 −22  J
> 1.2 meV
Molecular vibrations
Infrared spectroscopy , Raman spectroscopy , infrared astronomy
Mid infrared 3.0 µm 50 µm 6 THz 100 THz > 4.0 · 10 −21  J
> 25 meV
Carbon dioxide laser , quantum cascade laser Thermography
Near infrared 780 nm 3.0 µm 100 THz 385 THz > 8.0 10 −20  J
> 500 meV
Nd: YAG laser , laser diode , light emitting diode Remote control , data communication ( IRDA ), CD
light red 640 nm 780 nm 384 THz 468 THz 1.59-1.93 eV Radiant heaters ( incandescent lamp ), gas discharge ( neon tube ), dye and other lasers , synchrotron , light-emitting diode
Excitation of valence electrons
DVD , laser pointer , data transmission ( optical fiber )
Red, green: laser level ,
lighting ,
colorimetry ,
photometry ,
red, yellow, green: traffic light system ,
purple: Blu-ray disc
orange 600 nm 640 nm 468 THz 500 THz 1.93-2.06 eV
yellow 570 nm 600 nm 500 THz 526 THz 2.06-2.17 eV
green 490 nm 570 nm 526 THz 612 THz 2.17-2.53 eV
blue 430 nm 490 nm 612 THz 697 THz 2.53-2.88 eV
violet 380 nm 430 nm 697 THz 789 THz 2.88-3.26 eV
UV rays Near UV (" black light ") 315 nm 380 nm 789 THz 952 THz 3.26-3.94 eV Gas discharge , synchrotron , excimer laser , light emitting diode Black light fluorescence , phosphorescence , bank note checking , photolithography , disinfection , UV light , spectroscopy
Medium UV (" Dorno radiation") 280 nm 315 nm 952 THz 1071 THz
1 PHz
3.94-4.43 eV
Far UV 200 nm 280 nm 1 PHz 1.5 PHz 4.43-6.2 eV
Vacuum UV 100 nm 200 nm 1.5 PHz 3 PHz > 9.9 · 10 -19  J
6.2-12 eV
XUV tube , synchrotron , nanoplasm EUV lithography , X-ray microscopy , nanoscopy
EUV 10 nm 121 nm 2.5 PHz 30 PHz > 5.0 · 10 −18  years

10.2-120 eV

X-rays 10 pm 10 nm 30 PHz 30 EHz > 2.0 · 10 −16  J
> 120 eV
X-ray tube , synchrotron

Excitation of internal electrons , Auger electrons

medical diagnostics , security technology, X-ray structure analysis , X-ray diffraction , photoelectron spectroscopy , X-ray absorption spectroscopy
gamma rays 10 pm 30 EHz > 2.0 · 10 −14  J
> 120 keV
Excitation of core states
medical radiation therapy , Mössbauer spectroscopy