Also very true, but for the purposes of this thread here we'll just say that without getting into ridiculous amounts of physics (that not everyone even cares about) that the thing that separates a laser light source from all other light sources is that lasers tend to be more coherent, fair enough? Sometimes you just want a simple answer, ya know?
If that is blatantly incorrect, then please tell us what is it that separates a laser from all other light sources? Or are we all delusional and lasers are exactly the same as any other light source?
Here's a few quotes:
Quote from
wikipedia:
"The laser's beam of coherent light differentiates it from light sources that emit
incoherent light beams"
____________________________________________________________________
Quote from:
Quantum properties of light
"Coherence is one of the unique properties of laser light. It arises from the
stimulated emission process which provides the amplification. Since a common stimulus triggers the emission events which provide the amplified light, the emitted photons are "in step" and have a definite phase relation to each other. This coherence is described in terms of temporal coherence and spatial coherence, both of which are important in producing the interference which is used to produce holograms.
Ordinary light is not coherent because it comes from independent atoms which emit on time scales of about 10^-8 seconds. There is a degree of coherence in sources like the mercury green line and some other useful spectral sources, but their coherence does not approach that of a laser."
___________________________________________________________________
And my personal favorite from wiki answers (because of it's simplicity):
http://wiki.answers.com/Q/How_is_a_laser_different_from_other_light
"A laser is different in three main ways:
1- The light emitted from a laser is monochromatic, that is, it only has one wavelength (color). Ordinary light on the other hand, is a combination of many different wavelengths (colors).
2- It is coherent, that is, the waves of light of the laser are in phase. Just like two sea waves when they are both at their maximum height, all waves of the light in a laser are exactly at the same amplitude, all time.
3- It is highly directional. Laser light is emitted as a narrow beam in a specific direction. Ordinary light coming from the sun, a light bulb or a candle is emitted in various directions from the source. Since laser rays are so concentrated they also have much more brilliance than rays from other sources."
although we've already discussed how not all lasers are strictly monochromatic (multi-line emissions, diodes and other exotic laser systems)
_______________________________________________________________________________________________
And let's not forget there are more than one type of coherence:
Encyclopedia of Laser Physics and Technology - coherence, coherent, light, spatial and temporal coherence, monochromaticity
_______________________________________________________________________________________________
And you can also just google "difference between laser light and ordinary light" and tell us what the most common answer is.
So you'll forgive me for not accepting that you know better that all these web resources and the people behind them..
