Free-electron laser
Videos
A free-electron laser is a fourth-generation light source producing extremely brilliant and short pulses of radiation. An FEL functions much as a laser but employs relativistic electrons as a gain med
The free-electron laser FELIX at Radboud University, Netherlands
The undulator of FELIX
Laser
Videos
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser originated as an acronym for light amplifi
Free-electron laser
…free-electron laser (FEL) is a fourth-generation light source producing extremely brilliant and short pulses of radiation. An FEL functions much as a laser but employs relativistic electrons as a gain medium instead of using stimulated emission from atomic or molecular excitations. In an FEL, a bunch of…
A telescope in the Very Large Telescope system producing four orange laser guide stars
A laser can produce a very narrow beam of light of a single wavelength, in this case, green.
A helium–neon laser demonstration. The glow running through the center of the tube is an electric discharge. This glowing plasma is the gain medium for the laser. The laser produces a tiny, intense spot on the screen to the right. The center of the spot appears white because the image is overexposed there.
Red (660 & 635 nm), green (532 & 520 nm), and blue-violet (445 & 405 nm) lasers