I want to build a laser

[cwes99_03]

You don't need to have an arc. The gas will be excited by an energy field. An arc will only produce enough energy to get you into trouble.

Instead using some electric pads (metal plates with some insulation on the outside to prevent arcing in the open air) on either side of the tube to induce the electric field.

 

Additionally with your design you will have an arc from top to bottom not side to side. A single long conductor on either side of the tube (turning the thing into a capacitor) will be sufficient and require a lot less current and voltage.

 

There are gas filled tubes for arc lamps that have a metal terminal on each end hooked up to an electrode causing an arc to pass through the internal gas. These run at pretty high wattage and can be dangerous to those who don't know how to operate them.

[Turtle]

There are gas filled tubes for arc lamps that have a metal terminal on each end hooked up to an electrode causing an arc to pass through the internal gas. These run at pretty high wattage and can be dangerous to those who don't know how to operate them.

 

This is a mis-representation. Your above description describes no more nor less than a standard fluorescent tube rated at 40 watts or less.

 

I was going to use a laser pointer to align them, planning on using polished aluminum, copper or steel as the mirror....

 

Could I use a fluorescent light transformer for a tiny laser or do I have to wait (weeks) for my neon sign transformer? The little guys get hot, how many volts and mA come out of the standard fluorescent light fixture?

How hot does your LASER pointer get? How small is it? How much power does it draw? The point is you don't need a lot of power to make a LASER.

The power specifications for fluoresent light ballasts are printed right on them.

Great project idea; keep us posted.:)

 

PS Here's some data on ballast circuits:

http://members.misty.com/don/f-lamp.html

[Zippiot]

Lets say I want to make a "tiny" gas laser out of pvc pipe, prolly water cool is as it will get hot.

 

If I snag a transformer off of a fishtank hood, I should be able to make a laser about 4 inches long, then if I use some sort of plate on the inside to carry the elctricity...anyone think the little transformer could produce enough volts to lase the gas? Gas will msot likely be CO2, as I have easy access to it. Others gasses like He and Ar would have to be purchased from a welding store and I hate driving there...

 

Or if I use the system I pictured, but rig it left side is the all connected and right side is all connected together....

[cwes99_03]

http://en.wikipedia.org/wiki/Arc_lamp

[cwes99_03]

Hey quick thought about it. Wouldn't you want the light emitted from the aperture end to actually pass through a second aperture?

 

Thus any difraction at the first aperture will be removed by the second aperture. (I'd say separating the two apertures by about 3 cm if you have a pretty small first aperture.) It's been 6 years since I played with lenses and apertures.

[Zippiot]

So have a second lens after the first, adjustable so it can be fine tuned...doesn't sound bad.

If the thing is made of pvc pipe that will eb easy, just *** in a screw on cap after the first lens so it can be screwed in or out.

 

ok lets try this:

 

A pipe of pvc pipe about 4 inches long. At one end is a cap, at the other is a coupler (has a tiny stop inside to prevent the pipe from going all the way through) and on the other side of the coupler is a screw on cap. At the capped end of the pvc pipe is a mirror and a polished washer. At the end of the coupler is another polished washer and a lens, then in the screw on cap is another lens. Each washer is attatched to the power source, and the whole tube is sealed (leaving only the screw on cap exposded to the elements) and filled with gas.

Turn on the power and hope it works!!!

 

Make sense or should I draw a pic?

[Turtle]

Make sense or should I draw a pic?

Please by all means provide a drawing to clarify your description.

Inasmuch as this is a science forum I must revisit the mis-information put forward by CW. He said:

There are gas filled tubes for arc lamps that have a metal terminal on each end hooked up to an electrode causing an arc to pass through the internal gas. These run at pretty high wattage and can be dangerous to those who don't know how to operate them.

I said:

This is a mis-representation. Your above description describes no more nor less than a standard fluorescent tube rated at 40 watts or less.

He then posted the Wicky article on arc lamps as his support. Now my point is that he was and is wrong because he said the requirement is high wattage and the fact is that it requires high Voltage which is why I pointed out the error to begin with. The two are not interchangeable and making that mistake in designing or evaluating a circuit is unacceptable. Watts = Volts * Amps.

At any rate, by all means make and post the drawing as an attachment so we can clarify any other such errors as may exist.:)

[Zippiot]

Ok so the light blue is a lens (glass or salt) and the dark blue is the mirror (copper, aluminum, steel or silvered glass), the light grey is the polished steel washer and the rest should be self explanitory...

Wrong pic if anyone saw it before I fixed it :)

 

[Zippiot]

I have been looking at different compressed gasses and wondering if any would also work in the laser?

 

Stuff like:

Dust-Off (difluoroethane)

Nitrogen (from a compressed source)

Oxygen (just wondering)

Propane/Mapp (in a no oxygen environment it shouldn't explode or burn)

 

I have some chemicals that, when mixed, might give off some interesting gasses...don't want to be too specific though. Anything that can mix with 90% sulfuric acid or 30% HCl to make an interesting gas?

[Zippiot]

One More Thing:

Many homemade CO2 lasers have an adjsutment on the mirror side and the lens side, so I could use the same method for adjusting the lens on both sides, just one side has a mirror and not a lens.

 

Picture this

 

[Turtle]

One More Thing:

Many homemade CO2 lasers have an adjsutment on the mirror side and the lens side, so I could use the same method for adjusting the lens on both sides, just one side has a mirror and not a lens.

 

Picture this

 

Mmmmm...well at least if it doesn't lase you can convert it to a potato gun.:) Has anyone specified that the mirror needs to be a front silvered mirror? :doh: I think it matters a lot. :lol:

[Zippiot]

That depends entirely on the gas filling the laser...silver only reflects certain wavelengths (like a co2 laser would pass right through I think); how would you silver a lens just melt some silver solder over it and polish?

 

Hey if the lens doesnt reflect enough...might try a piece of an old cd. They let through light but reflect much of it back (more than 50%).

[Turtle]

how would you silver a lens just melt some silver solder over it and polish?

Uhmmmm....no.:lol:

http://www.make-stuff.com/formulas/mirrors.html

[Zippiot]

Sweet! Now if I just had a calcinator so I could turn sulfuric acid into nitric acid...then find some silver and that salt it called for...

 

I doubt I will need a silvered mirror though, most CO2 lasers dont have them

[Turtle]

Sweet!

I doubt I will need a silvered mirror though, most CO2 lasers dont have them

Here I have to point out a technical error in your second sentence above. :) :lol: "Silvering" is a generic term for any reflective coating whether applied front surface or back surface and regardless of the substrate it is applied to. This means if something is a mirror it is silvered no matter what metal or other material is applied to increase reflectivity, and this includes CO2 LASERs. Just as with the wattage/voltage mistake, mirror characteristics demand the proper terminology. :doh:

[Zippiot]

I totally missed my mistake in my post, I meant silvered "lens". See the diff?

 

I am allowed 2 brain farts a day, 3 if its early...

 

I meant that, in most CO2 lasers, the natural reflectiveness of glass or halite (salt) should be enough to lase, as a CO2 laser has a high enough "gain" to lase with a 4% reflection on the lens side. Did I use gain correctly still learning some new terms :cup:

 

High gain lasers sometimes dont even need a mirror (look up nitrogen laser) but many solid state lasers need a mirror on one side and a partial (usually 50%) mirror on the other. This lets only the correctly flowing photons emitt and form the beam...

 

Was any of that right just got back from physics class and my mind is a pile of mush...

[Turtle]

I totally missed my mistake in my post, I meant silvered "lens". See the diff?

 

I am allowed 2 brain farts a day, 3 if its early...

 

I meant that, in most CO2 lasers, the natural reflectiveness of glass or halite (salt) should be enough to lase, as a CO2 laser has a high enough "gain" to lase with a 4% reflection on the lens side. Did I use gain correctly still learning some new terms :cup:

 

High gain lasers sometimes dont even need a mirror (look up nitrogen laser) but many solid state lasers need a mirror on one side and a partial (usually 50%) mirror on the other. This lets only the correctly flowing photons emitt and form the beam...

 

Was any of that right just got back from physics class and my mind is a pile of mush...

I'm gettin' a bit mushy this time of night as well, but the info in your last two paragraphs on gain is new information to me and sounds right as rain.

 

On the silvered lens difference you propose at the heading there remains an error of expression. Any silvered and/or reflective substrate is a mirror regardless of the shape of the substrate, be it lenticular or optically flat. Does that specification make sense to you?