The green HeNe, how it works
well...@kuhub.cc.ukans.edu
it produces strong lines at 543Nm (green), 594Nm (yellow), 614Nm (orange),
632Nm (red, which is the strongest) and 1.115u (IR). The green HeNe doesn't use
a crystal as the line is already there. What it does use is mirrors
dichorically tuned to that wavelenght (543Nm). But since the lines other than
red are weaker, a larger tube must be used to produce an output at that
frequency. A .75mW HeNe is actually a 10mW red HeNe with it's mirrors tuned to
only pass the 543Nm line. On the up side though, a .75mW green HeNe appears as
bright as a 5mW red HeNe to the eye as the eye is more sensitive to green than
red. Therefore, the laser is classified as a CLASS IIIb laser, even though it's
output is .75mW. The crystal doubling is used for ND-YAG systems that emit at
1061Nm or IR. the cryatal doubles the output within the lattice structure for a
output of 532Nm or green as well. Now the argon laser can produce several lines
as well. For example, it has strong lines at 458Nm (deep blue), 488Nm (blue)
and 514Nm (green). By using a dichoric filter or diffraction grating, these
lines can be broken into thier separate componets. The argon laser can emit
these at the same time whereas the HeNe can not. But argons are power hogs. For
100mW out, about 1.5KW of power must be pumped into it. The remainder of the
power is in the form of heat and the heat has to be removed from the tube by
either forced air or water cooling. Argons are also many time the cost of a
HeNe due to the power supply (about +140vdc at 10 amps running, 12Kvdc strike
voltage) for a 100mW argon and the tube and optics. The tube is berilium oxide
which draws off the heat better and the cooling required for it. But for all of
thier pitfalls, a argon laser is the most striking in color and it is used the
most for commercial laser light shows.
Hope that helps some on the green HeNe laser ;-)
-=-=- Wes =-=-=
John Sevinsky
but I have never seen any green or yellow ones. Does anybody know of a
place where I can buy these lasers?
Albrecht Jander
>I have seen many red HeNe lasers for sale in several catalogs which I have,
>but I have never seen any green or yellow ones. Does anybody know of a
>place where I can buy these lasers?
I beleive I saw some in an Edmund Scientific catalog.
>
>John
>jsev...@digi.lonestar.org
Bill Squire
> I have seen many red HeNe lasers for sale in several catalogs which I have,
> but I have never seen any green or yellow ones. Does anybody know of a
> place where I can buy these lasers?
By far the cheapest source I know of is Halted Specialties in Santa Clara.
A call to +1 408 555 1212 should get you the number. I distinctly remember
$250 for any colour you want two years ago when I lived in that area. The
green put out about 1.5mW which was by far the brightest I've ever seen in
green HeNe. (Ofcourse no match for a 5W argon!) Colours available were:
Std red ($15up) red/orange, orange, yellow, green and there was talk of a
even shorter wavelength, but I don't know how. A local person in the Silly
Valley builds them by modification to standard red and does a very fine job
of it. Check them out!
Bill