On Jul 2, 2:35*pm, Cecil Moore wrote:
On Jul 2, 3:21*am, "Szczepan Bialek" wrote:

The word "laser" is probably common *name for the all atificical light
sources.

No, it is not. From answers.com: "Definition: laser - Any of several
devices that emit highly amplified and coherent radiation of one or
more discrete frequencies."

From Wikipedia: "Light Amplification by Stimulated Emission of
Radiation (LASER *or laser) is a mechanism for emitting
electromagnetic radiation, typically light *or visible light, via the
process of stimulated emission. The emitted laser light is (usually) a
spatially coherent, narrow low-divergence beam, that can be
manipulated with lenses. In laser technology, 'coherent light' denotes
a light source that produces (emits) light of in-step waves of
identical frequency, phase,[1] *and polarization. The laser's beam of
coherent light differentiates it from light sources that emit
incoherent light beams, of random phase varying with time and
position."
--
73, Cecil, w5dxp.com

should we even bring up its close cousin, the MASER? I particularly
like this definition:

"MASER stands for Microwave Amplification by Stimulation Emission of
Radiation. A LASER is a MASER that works with higher frequency photons
in the ultraviolet or visible light spectrum"
from: http://einstein.stanford.edu/content/faqs/maser.html