Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Where to start? HeNe Gas Laser

I picked up a nice starter HeNe and PSU for $40 on eBay... :whistle: the deals are there, it's just a race to find 'em :beer:
 





Ok here i go:
A gas laser (specifically the HeNe) is a sealed tube filled with 1:5 He:Ne - 1:10 He:Ne. basically the power supply excites the gas at each end of the bore through the anode (+) and cathode (-) and pushes electrons into an excited state, when one gets excited another gets excited (Stimulated Emission). This all occurs in the bore of the tube and at each end the the light is collimated and bounced off of two mirrors, the high reflector (99.99 percent perfect) and the output coupler (98-99% perfect). The mirrors can be mounted on the actual tube or a window in the tube can let collimated light pass into the external cavity before hitting the OC and/or HR. The getter, also used in computer vacuum tubes as well as CRTs is a residue left behind from decomposed "Shiny Spongy Stuff" that has been decomposed to react with oxygen left in the tube after vacuum pumping. not sure what a spider is, please tell me i would really like to learn. The difference Between the 632.8nm tube and the 543.5nm tube is orthogonal polarization (including length of tube), neon gain bandwidth, and most 543.5's will require more power for the same output power. Bore size also can affect the type of beam, I found this picture of a bunch of beam types:
LaserModes.png
'

I hope that is a sufficient explanation. I am no Dr. Sam but i hope youll throw a price at me (I tried).
 
Last edited:
All that of that was spot on.

The spider and getter is the metal portion of the tube. The spider in the metal on the cathode end, under the glass. The getter is a small piece of metal next to it that absorbs impurities during the ionization process. The ions of other gasses get absorbed into the metal.

Also, gas fill on a 543.5nm tube vs a 632.8nm tube is slightly different, as is pressure. Though that's all proprietary.
 
Last edited:
If I get a good enough tube to give away, I will sell it to you for a bargain :) If not, I'll scout eBay for a tube that I'd buy, and send you the link(s). :)
 
Thanks bloom, i may have learned a bunch but it kept me from doing my REAL Homework.
 
Sorry :(

At least you're in classes. I had to buy all of my own college texts to self teach myself.

That being said, I need to start doing that more. Been slacking!
 
yeah, i noticed you were staring at your wall for hours waiting for the 609 to flicker in. good use of time by the way. haha
 
I could also use some gas laser deals :p I could only find one eBay listing for a yellow HeNe... what magic search terms am I forgetting? :thinking:
 
You must log in or register to reply here.


Back
Top