A few days early as requested... my step-by-step instructions video for making the TEA laser is up. Check it out. Made from parts from around the house and the hardware store.
It was cool seeing the laser in the fluorescent liquid. Rather than just seeing the dots you could actually see that there was a beam. I think it really helped illustrate that this was, in fact, a laser.
They're often used in biology and chemistry labs as sources of coherent ultraviolet light, which is the laser beam that they produce. They're also very easy lasers to make without requiring any specialized parts, so they're fun for hobbyists like me to make.
From what I see with mine, you have to be able to produce a spark with a lot of current in it. That's in order to produce enough electron collisions with nitrogen molecules in the long spark gap in order to get the lasing to work. I don't have a fly swatter but from what I've seen of them in videos, I don't think they'd have the current. The sparks would be too thin. The sparks I need to produce to get it to work are pretty loud, thick and bright.
Very cool Rimstar! Thank you for showing how to make it! Its really cool how simple it is. I'm still curious what would happen if you blew some helium over the laser gap. Would it change the color/wave length of light? Thank you!
Oh, I don't think he's debating whether or not it's actually lasing. The answer to that is that when adjusting it to get it working, sometimes you get the spot on the paper and sometimes you don't, and yet all of the time there are still plenty of sparks in the lasing spark gap.
Some of the web sites I read last week suggested a lens could yield improvements. Especially if your getting spread over distance, even at closer range a lens can help. You can also focus to a smaller point. I'd be guessing a fairly low bend lens.
I'm thankful that there are 405nm lasers out there that can give us the exact same fluorescent effect as your TEA laser. While 405nm is not technically ultraviolet, at least the violet light that they emit is actually very close to the UV spectrum so it behaves very much like the ultraviolet light from the one you're using. I would love a TEA laser but I don't think I could deal with all the steps especially with constantly blowing the capacitors.
Thanks! I don't know what'll happen if you blew helium over the gap. I do know that if you add helium in a high pressure environment then the color/wavelength will 427.1nm instead of around 337.1nm. Not something I've tried, just something I've read.
Thanks, nice video! You use a vice and turning the wire to straighten it out. Another, simpler way to straighten a wire is to clamp one end in the vice and pull on the other end with pliers or similar, stretching the length of the wire by a couple of percent. The metal lattice 'learns' the new pattern and you end up with a perfectly straight wire.
Henner Zeller I'd actually read about that wire straightening technique at the time but didn't think it would work as well as claimed. Now that you mention it I'll have to try it next time. Thanks.
I think I'd need more than capacitive measurements to assess the scope of photon generation. Does an aperture make sense with a laser where most of the photons make only one pass?
You're a genius, youtube should pay you salary! Thanks for broadening my mind yet again with this awesome video! Can't wait to put my TEA laser together!
But I guess if you have a 45cm diameter sphere or bucket and you connect the positive output of your fly swatter to the INSIDE of the sphere (same principle as a Van de Graaff generator dome, Faraday ice pail effect), you could accumulate enough charge on the sphere. Then, where I have the cap nut shown my spark gap in the video, use the sphere instead. I haven't tried that but theoretically it should work.
Cling wrap is awfully thin. I haven't tried it but I'd imagine you'd need a few layers. You'd have to make sure there are no wrinkles. Let us know if you try it.
+JBCACC It is hard to get working and takes time and patience. Try with different widths of the lasing channel (the long gap between the two aluminum angle pieces.) You can still get sparks like you're getting with smaller or wider gaps. Also, increase the other spark gap so that there's more power each time. Those are the two things I adjust to get mine working. PS There's no Reply button under your comment because of your Google+ settings. - go to your Google+ page, - in the top, right corner click on your thumbnail icon, - in the popup that appears, click on "Settings". - for the 2nd question down "Who can comment on your public posts?" set it to "Anyone".
JBCACC What are you using for your power supply? The capacitor plates have to be very close together to work so what are you using as your dielectric (the polyethylene or transparency film)?
RimstarOrg I have built one from an old computer power supply and a flyback, so i should have enough power in the system. I think the max. V i can get is about 50kV. I´m using two transparency films. should i try it with only on?
JBCACC Yes, try just one transparency film. The dielectric needs to be really thin in order to meet the timing requirements, and yet it has to be able to withstand the voltage. I got it working with just one transparency film.
Hi! I am still amazed of your so high skills to teach and demonstrate. :d Still very precious skills and useful for The General Interest. Thanks a lot for Been Here And To Communicate As You Do! Sincerely.
They come in many thicknesses, we have tried the thicker ones from 42 inch tvs (excluding the thicker 2mm acrylic panels ) smaller screens use thinner. But in testing we have found it to be one of the best we have found for withstand/vs thickness. I am a laserist by trade and play with HV as a hobby and would love to exchange ideas. I am considering putting a TEA laser into a pointer which brought me to this video.
One quick question to ask, does the ion channel have to travel along the plates or can you store charge in a reserve capacitor. ( does the ion channel have to travel from opening A to opening B or is is simultaneous discharge along the capacitor surface? ) Asking because in a pointer if I cannot use a reserve area i am going to have to do some fancy capacitor geometry.
Great to see how easy it is to make. I liked the demonstration of the thread tap set. I really am tempted to try this. I think my flyback can do it. I Wonder what the dielectric strength of quality cling wrap is? I think I've seen HV caps made with it somewhere? Metric values where nice too :)
A friend and I are trying to rebuild this one, but we're stumbling across a little problem. Our voltage source doesn't deliver enough voltage for the laser to work. So we're wondering, do we need to use DC voltage or not?
Yes, you need DC because you have to charge up the spark gap that's on the side of the TEA laser (the one which I made using a piece of angle aluminum and a brass nut). As long as you can charge that up then it should work. Of course, you can make that gap very small and then you won't need much voltage but when it sparks, there won't be enough energy to power the laser. So there is a minimum gap size you need, and therefore a minimum voltage (I don't know what that is). When testing it, I have to gradually make this gap bigger and bigger until the laser starts working. Keep in mind that depending on your power supply, it may take a while to charge the spark gap. In this other video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-9huUsYDJZrM.html, I use a Wimshurst machine and it took around 10 seconds to charge up while the gap size was large enough for the laser.
I didn't do much testing with the transparency film, only enough to try it out, so maybe two minutes altogether. It did seem more robust but that might be because it had no visible flaws in it whereas the polyethylene came off my roll and had visible flaws. I really wanted to include it in the how-to-make video because it's easier for people to find than the polyethylene.
Darn! I made a really good capacitor with nice big consistent sparks, and then my flyback burned out! oh well, i think its time i work on a nice proper HV power supply.
Did you also burn out your transparency film? How will did it hold up to the high voltage? That is what I had used when experimenting with the TEA a long time ago, but did burn through them.
Hi, I want to implement this into my science fair project, but I need to test a certain variable. I was thinking of changing the distance between one of the spark gaps, or the amount of voltage, or the amount of resistance between the long spark gap. Do you think any of these may add danger to the experiment (e.g. blowing holes through the dielectric) or make the laser simply not work? Thank you
All of these things may make the laser simply not work. It's fairly finicky and takes fine adjustment to get everything just right and make it work. In my experience if the voltage/spark gap distance is too small it won't work and too large you start blowing holes through the dielectric. The only variables I can think of you can play with while the laser keeps working reliably is the cross sectional area of the beam at different distances, or maybe the affect of passing through different liquids.
Hi, i build this TEA laser but i cant recognize, see or messure a laser. its sparks exactly like in your video, at bouth ends and a little bit in the middle. Do you know what my misstake could be? Its like in your video but no laser point :( sorry for my english
HI.! I AM NEW TO LASER SCIENCE AND HOW THEY WORK, HOW WOULD YOU START A LASER RUST REMOVAL. I AM STARTING FROM SCRATCH AND I AM CURIOUS WHERE I SHOULD START LEARNING THINGS TO CREATE ONE MAYBE YOU COULD POINT ME OUT TO THE RIGHT DIRECTION. THANKS.! ?
HI, I have always heard that the power in these lasers is enormous. Do you know if the beam (with an end reflector and focusing lens) can ionize the air enough near a high-energy capacitor spark gap to produce isolated triggering?
I suspect the power is low since I could put my hand in the way of it and feel nothing. But then again, it lases for only a brief time each time. Either way, I don't know if it can ionize the air enough.
You can get them here www.amazing1.com/categories/parts/miscellaneous.html . Mine actually came as a part of a high voltage power supply which I also bought from that website. Another source of roundish metal things I've found is to look for drawer knobs in places like Home Depot.
It's for delaying the charging of the 2nd capacitor; the 1st capacitor is the one with the spark gap from the power supply. That way the capacitors will be at a different polarity long enough for the corona and sparking across the lasing gap to happen.
+RimstarOrg yes but I'm sure you can measure the capacity of the aluminium sheet capacitor and will get something like 0.05-0.1 uf. I plan on using 5*20kv capacitors to have 0.5 uf of capacity. I am sure that this can discharge with no problem. I hope to make a laser induced plasma channel for an electrolaser.
I'm so disappointed :P I actually thought you'd got tea to laser. That's what I thought was in the bags, tea leaves (Yes, _really_ :P ) (facepalm) Fascinating video though, I didn't even know you could cause the nitrogen in the air to "lase" like this.
RimstarOrg Oh thanks, I appreciate that. Really :P:P Seriously though, it's gonna be a race between you, and Ben Krasnow of Applied Science to turn tea into a viable laser ;)
Hey Dude! That's not a laser! It's just a bad Electrical spark. I can do that echo friendly with an empty cigarette lighter. Mr. Nikola Tesla many decades ago made better interesting experiments. You should make demos of his experiments.
You're partly right. It's not really a laser, but rather a super-radiator. But the only difference is that there is no cavity because the lifetime of the population inversion is so short that you can't build one. But still, the nitrogen laser is probably the strongest (and the most dangerous) "laser" you can build at home.
