A YouTuber by the name of [1kreature] is doing some excellent research into building his very own 3D printed laser tube.
It all started after he managed to find an extremely high voltage pulse driver. In his video he assures us we should never buy one. He then designed some 3D printed fittings for a clear acrylic tube that allow for pneumatic and electrical connections. Using a hand pump to create the vacuum inside was the most difficult, so he quickly upgraded to a proper industrial vacuum pump.
Apply the vacuum, turn on the pulse driver… and well… see for yourself!
Now building a home-made CO2 laser is nothing new, the technology has been around forever, and we’ve seen a few hardware store laser builds which are awesome, but we’ve gotta say, we’re pretty impressed with the sole fact that most of this one is 3D printed.
We might just be seeing some 3D printed laser cutters soon!
Looks like a neon sign, no LASER.
Indeed, there might be laser activity in there, but we won’t see it as is should be a CO2 laser that gives of IR light.
It looks like he will not be using high power densities, so he might get away with using printed parts. If that is all he has to fabricate his parts, I’d say go ahead, be safe and have fun!
Have you ever seen a CO2 laser tube? The tube still ignites with plasma, the actual beam that comes out is invisible — but you can definitely see activity in the tube!
His camera can likely see IR though ;P
The article points out that he is doing research into building a CO2 laser, not that he had accomplished it. This is just the point at which a vacuum is pulled and the pulse driver fires. He would still need to set up parallel mirrors at either end of the tube (apparently coming up with suitable reflective and semi-transmissible reflective surfaces/optics is not an easy task) and he would need a proper mixture of CO2, nitrogen, helium, and possibly hydrogen or xenon for the tube.
In any case, I wish him much luck!
To make it a laser he doesn’t have to do much more, only add two mirrors at the extremities of the tube and punch a hole in the center of one them. Maybe he already have that, I didn’t read TFA.
not so simple, it’s not just flat mirrors, you have to make a Fabry Perot cavity with extreme tuning
You don’t care about creating a proper resonator if the gain from the stimulation phase is greater than the loss in the resonator, I never built a laser so I do know if it will be the case here. Then you would just need to do the spatial filtering outside the laser tube using the standard fourier optics filtering technique (lens + pinhole assembly).
just said not so simple,
Mirrors – HR: Copper coated, concave, f >= twice the distance between the mirrors ; OC: Germanium or hole in glass and IR-transparent window of NaCl , CaCl, KCl, or BaFl – but note that all of these are hygroscopic so must be stored with a desiccant to keep them dry and in an environment of less than 35 percent relative humidity at all times, planar. (Germanium is preferred but may be expensive.) Three screw adjustable mirror mounts
He uses a neon transformer to create plasma in a tube… where is the laser?
Very close. Needs an optical cavity and lasmix.
It’s not really “very close”. He’s built a gas discharge tube — something that was around for decades before the first lasers were constructed. This is like saying someone is “very close” to building a spaceship because they have a rocket engine.
A spaceship is just an empty can attached to the front of the engine. I’d say getting the engine done is the majority of building a spaceship, you could just silicone up the holes in a bus and stick an engine on the back and it’d be a spaceship.
MAGIC SCHOOL BUS!
That “DC 3.6V-6V To 400kV – 600KV Boost Step Up High Voltage Power Generator Module” is scary.
Yeah, but they are pretty cheap. I don’t know how long they last though.
http://www.aliexpress.com/item/Free-Shipping-DC-3-6V-6V-To-400KV-Boost-Step-Up-Power-Module-High-Voltage-Generator/32359263178.html?spm=2114.01020208.3.2.IvaGqk&ws_ab_test=201407_1,201444_6,201409_1
Yea, but they are not particularly good either, 60 seconds of usage before you must power down to avoid the heat build-up from destroying the unit.
“Due to power, the internal heat is not easy , every power-on time should be controlled within a minute.”
400KV? I could see 4KV but not 400KV. Am I missing something important?
Ancient Chinese exaggeration. It’s probably more like 40KV.
A laser in vacuum ? not possible.
Care to explain for those of us not so well versed in laser theory?
It’s to do with the excited states of the atoms that give off the photons. If you haven’t got any atoms, that won’t happen.
I think you misunderstood Jacques’ rather obvious statement to mean something else. And I think Jacques misunderstood the purpose of the vacuum pump, which is to suck out the air, before the CO2 is let in.
No, I didn’t misunderstand. I have not studied how lasers work, so I asked the question. I genuinely didn’t know that lasers cannot be created in a vacuum.
Thanks for explanation, it makes perfect sense to me now.
Correct, i was misled by the text “Using a hand pump to create the vacuum inside…”
Lasers are possible in a vacuum, are you telling me that photons can’t travel in the vacuum of space? how do we get light from the sun… What isn’t possible is a visible laser, there is nothing that causes the photons to scatter to hit our eyes. Well unless it was directly pointing into your eyes. You could most likely see where the laser hits the target because at that point light is reflecting off a surface in many directions.
Laser *beams* are of course possible in a vacuum. You aren’t going to get lasing activity inside a completely evacuated chamber. (Free-electron lasers notwithstanding)
Nah. The way lasers work is simply like this. In the tube is a gas medium that is energized by high voltage plasma arcs and during that excited stage the gas emits light. On both sides of the tube are mirrors which reflects the light that hits them and the ones that hit the mirrors straight on bounce back and forth and are considered polarized since they are going in the same direction. One side of the laser tube has a hole for the polarized light to escape. This is an over simplified description but that is essentially how it works. No gas, no light, no laser.
And an incorrect over simplified description at that.
Actually, you can make a pretty amazing laser in vaccuum:
https://en.wikipedia.org/wiki/Free-electron_laser
(Also known as a “wiggler laser”.)
if you have electrons, it’s not vacuum !
You really cant have a complete vacuum like you imagine it to be. There are several grades of vacuum, low, high, and ultra high vacuum. To have an electron beam you really need to have a high to ultra high vacuum otherwise the electron just ionize the remaining gas molecules in the chamber. Even at UHV levels (10^-9 torr or the moon) there are still about 400000 molecules per cubic centimeter.
Err…. how well does this actually retain the vacuum over time?
Not well I’m sure. He wouldn’t be able to run it as a sealed device.
Just buy a real Co2 laser tube. I don’t think this project is going nowhere. Only in the bin in the end. Sorry this is no laser to me.
Your delightful encouragement is a wonderful addition to this site. You must be the happiest person alive.
Not everyone WANTS to buy something off the shelf because you learn stuff when you build it yourself. Back in the ’60s and ’70s there was a column in Scientific American called The Amateur Scientist that had plans for building your own lasers – a NeHe tube laser, a Hg vapor laser, a high power Nitrogen pulse laser using a spark gap and a Rhodium 6g dye laser to name the ones I can recall.
It would be nice if everyone @ Hackaday had University/Govt research grants to fund our hacking but that obviously isn’t the case.
It would be nice if Scientific American still had columns that matched The Amateur Scientist in quality.
I agree. Back in the day the articles were top notch, and very informative.
Oh yeah! I loved those. I bet they stopped printing them due to liability. I wanted to build the particle accelerator (a Van de Graf, some refrigerator pumps, and…) but I’m pretty sure if I had, I’d have died from something nasty before I turned 20.
See page 344 of https://archive.org/details/TheAmateurScientist — 344 by the printed page numbers, not the PDF page.
Would be a lot easier if he used argon instead of CO2… you can see the tube discharge, and the output wavelengths are mostly visible, blue and green. A little bit of UV, but the strongest lines are 514 and I think 488nm if memory serves me right. All other principals are the same.
Except that to use argon in a laser, you have to use the atoms of argon, with electrons ripped off, to make the wavelengths you are talking about. Google Argon ion lasers. Not an easy task to say the least! There is a reason they don’t use them much anymore, not only because of the materials required to build them being highly toxic, but their terrible efficiency.
Argon laser require very high current densities to work. To do this you either need BeO ceramic to make the tube or magnetic constriction. They also require a heated filament for thermionic emission.
There are plans out there to make a pulsed argon laser that discharges a capacitor through the tube to get the current necessary but the rep rate can be pretty low.