Lasers are neither a variation nor a form of plasma. Laser beams are composed of
photons which have been synchronized to all have the same frequency and move in the same direction. Lasers can be made very powerful and have found thousands of uses, from cutting holes in metal, patterns in stacks of fabric, to etching characters in the surface of materials. Very short wavelength lasers (i.e., ultraviolet) are used in photolithography of printed circuits. Lasers operate under quantum chromodynamics, like light, and are effected by electromagnetic forces exactly as is light, and are no more or less affected by gravity than regular electromagnetic radiation. They may have other names when they are emitted at other than optical (visible) wavelengths, such as masers, for "
Microwave
Amplification by
Stimulated
Electromagnetic
Radiation". Masers can be stimulated near stars where strong radio frequency (microwave) radiation may be present, that excites emission of monochromaticRF radiation. Water masers, in particular, have been observed in active regions near galaxies.
Plasmas are collections of
particles, some or all ionized, which behave according to Maxwell's and Lorentz's equations. While they will emit light when in their glow and arc modes, it is not always at precisely the same frequency and generally is not collimated to all move in synchrony in the same direction. Plasmas, like lasers, have been adapted to industrial processes that involve cutting, as well as welding, sputtering (ion deposition) and breakdown of toxic compounds for safe recycling.
Here is an article on "Mega-maser" in New Scientist:
http://www.newscientist.com/article/dn1 ... water.html
It has the drawback of describing the excited state of water as "warm" and that the emitted radiation is caused by thermal collisions, and that radiation from one water molecule "prompts" other "excited" molecules to emit microwaves at the same frequency. This seems far too tame a description of what must be fairly high energy processes that are not just warm fluid dynamics. Steam-punk at work in science!
Refer to Wiki article on "Astrophysical maser" for a good explanation of how plasma can form laser light, although it does not have the cavity and multiple passes through the amplifying medium that terrestrial lab lasers do.
Lasers can be used to cool hot, strongly-coupled non-neutral plasmas (Penning traps, sometimes used to create Bose-Einstein condensates). ref:
Physics of Strongly Coupled Plasma, pp 378-381, Oxford Science Publications, 2006, Fortov, Lakubov and Khrapak. ISBN0-19-929980-3
Any help?
Jim
