What are the various colors of lasers we have today?
LASER, of course, is short for Light Amplification by Stimulated Emission of Radiation.
This light is generally a collimated beam of coherent (all the waves moving in lock-step)
electromagnetic energy with a very pure 'color' or narrow bandwidth.
By referring to colors, the question is taken to mean colors in the visible range from
about 400-700nm. There are of course lasers with wavelengths in the infrared, masers that
emit coherent microwaves, and even x-ray lasers.
As for visible lasers, there are several types that emit in a variety of colors.
Semiconductor or diode lasers are the type we are most familiar with. These include red
laser pointers at about 650nm. Lasers near this color are also used in all computer and
music CD players. Diode lasers are now available in discrete colors from the infrared to
blue and into the near ultraviolet.
Many are familiar with the orange HeNe gas laser at 632.8nm. HeNe laser also come in a
green variety at 543.5nm. The following web page describes many more colors available
from gas lasers; http://php.iupui.edu/~jheacox/gasu.htm. Gas laser colors also span the
entire visible range at discrete wavelengths.
Dye lasers use an organic die in liquid solution as their lasing medium. Dye lasers have
a unique ability to be tuned over a broad range of colors. In fact, by the appropriate
selection of dye, any possible color in the rainbow can be produced. This web page,
http://exciton.com/laserwavechart.htm, shows a comprehensive chart of wavelengths produced by various dyes.
Scott Wilber, President, ComScire - Quantum World Corporation
'Physicists like to think that all you have to do is say, these are the conditions, now what happens next?'