Electromagnetic radiation is a natural phenomenon found in almost all areas of daily life. Examples include thermal radiation (in the form of warmth), x-rays and γ-rays emerging from radioactive decomposition. Electromagnetic radiation is also artificially generated by radio transmitters or mobile phones.
Electromagnetic radiation is produced by the movement of charged particles and travels in waves, but does not need a medium in which to travel. All light, including laser radiation, consists of electromagnetic radiation. The difference between each 'type' of electromagnetic radiation is the wavelength/frequency, as shown in the diagram below. In addition, shorter wavelengths (higher frequencies) have higher energies, hence exposure to x-rays and gamma rays is dangerous, but radio waves are harmless.
Electromagnetic radiation within the range visible to the human eye is commonly called light. In this general sense 'light' consists of electromagnetic radiation in the wavelength range between 380 and 780 nm (nm = nanometre = one billionth of a metre). This range is the visible spectrum. When all wavelengths in the visible spectrum are emitted simultaneously, this is perceived as white light. If white light falls on an optically dispersive element such as a prism or birefringent filter, the colours of the spectrum can be seen due to refraction. It starts at the short wave as the colour violet, turning to blue, green, than yellow and goes to the long wave, which appears as red. Beyond the long wave (red) of the spectrum is the near and far infrared range. Below the shortwave range (blue) is the ultraviolet range.
However, the term Laser-'light' refers to a much broader range of the electromagnetic spectrum: between 150 nm up to 11000 nm, i.e. from UV-'light' up to far infrared 'light.'
This information has been adapted from the LaserVision knowledge base. Laser 2000 is Platinum Partner of LaserVision.