How to build a laser in your living room. (Pt. 2)
ฝัง
- เผยแพร่เมื่อ 15 ก.ย. 2021
- Took a while, but maybe the real lasers were the friends we made along the way...
The design and build of a (now successful) pulsed Nd:Glass laser in the home shop. Check out Pt. 1 for more details
===Sources and Links===
LASERS Pt. 1: • Building a Solid State...
Great Flashtube calculator: www.fenixtechnology.com/fenix...
More flashtube design stuff: laser-caltech.web.cern.ch/rep...
Much better video on the functional details of lasers than I could ever make: • How a Laser Works
Awesome website with some info about Solid State Lasers: www.repairfaq.org/sam/lasercps...
The Bible:
www-personal.umich.edu/~andrew...
Info about flashtubes:
www.flashlamps-vq.com/Catalog...
@Applied Science's Ruby Laser:
• Ruby laser design process
===Attributions and Licences===
optical-cavity1.png By DrBob, CC BY-SA 3.0, commons.wikimedia.org/w/index...
"Ambience, Night Wildlife, A.wav" by InspectorJ (www.jshaw.co.uk) of Freesound.org
“The Root Of All Things” licensed via Music Vine: IAZ5UHXNLIKVXKR5 - วิทยาศาสตร์และเทคโนโลยี
I built a LIBS system in 2013 using a q-switched laser from an M1 Abrams tank. Still using it, does a pretty good job of elemental analysis. I sure wish some other people would take an interest in Libs. All you would need is a q-switch & probably reduce power and of course a spectrometer of some kind.
Been anxiously awaiting this upload.
Doing some spectroscopy was one of the ideas I had for something to do with this thing now that it works. Maybe in the future I'll revisit it...
Thanks for watching!
Awesome! Looks like using a camera as well, where I was assuming I'd need a linear CCD detector and a webcam wouldn't have a high enough refresh rate or something regarding gating when I asked about. Please update the broken links in the description. Looks neat!
@@jafinch78 you’d probably need a notch filter to remove the laser light as well
Been waiting for this one for a long time!! :) Keep uploading!
Thanks for watching!
You can add more flash tubes by adding eclipses in star shape around the Nd-glass rod where each of the eclipse shares a focal point with the rod. More power by spreading the energy across the flash tubes prevents the flash tubes from exploding. You will eventually come to the point where the pumping energy exceeds the maximal absobtion of the Nd-glass rod and the laser rod itself will shatter in itself. It goes from optically seethrough to milky opace because of the sudden difragmentation.
I don't speak English very well, but when I see someone doing this kind of super fabulous and crazy experiments, projects, I just can't contain myself from keep watching it. Also, awesome result, I liked it, thanks for the video!!
amazing video! would love to see more of your cool projects. Maybe a Spectrometer build with a TCD1304 and some optics :)
Well done! The work payed off
Awesome!! Your enthusiasm is contagious! Thanks for sharing.
Definitely worth the wait, glad I turned on the notifications. Best of luck on your next project Eric!
dude this goes so hard. thanks for sharing
Impressive! Very well done.
Great success! i literally have an epilog co2 laser right next to me. so awesome to make your own pulse laser! maybe someday ill make one since i have old worn out laser mirrors and lenses.
I guess you could try different Rods. I assume there are more, of course Ruby but other types.
nice. just getting home from work on a 30kJ 60TW megalaser with Nd glass rods as big as my leg to have a snack and watch some youtube videos....about Nd glass lasers 😆
Thing sounds like a beast! Us home gamers can only dream...
Thanks for watching!
@@EricThornton24 60 beam OMEGA system at UR's LLE. It's easily the most exciting time in the history of ICF research right now with LLNL's 2MJ NIF about to achieve ignition and high gain for the first time in history probably some time over the next few weeks.
You have my dream job. I wish I also worked with lasers. But it's fun to have as a hobby too.
Do you have any videos on your laser?
@@quidem666 well you can see a video of the construction of our 2 petawatt OPCPA OMEGA EP laser here, but there's really no video on the main 60 beam fusion system it's adjacent and connected to. maybe I'll make one some day...
th-cam.com/video/QOagieCvxio/w-d-xo.html
In the future please keep the same title for parts 1 and 2 so we can find it
Such an interesting project. Any plans on building it in, like , an etching device or something? What's the power (energy) of the pulse?
The razer blade drill says it all!!
Good work Man...congratulation ..my laser I preferred to buy the font in there...I used a tattoo removal and the display...to focus to using the 160mm engraving laser
GREAT VIDEO!!
I am working on building my own Nd:YAG laser with some surplus laser caivites and finally have everything I need to start setup. Would you provide your PFN and trigger circuit diagrams so I could have another point to look at and compare my designs with? Thanks, your videos were great and helpful!
Cool. Can you please share the links to buy the right things.
Very very cool, glad to see you were ultimately successful. Working on my own yag project here in the coming weeks and you had exactly the info I've been searching for on the output couplers and PFN. Im using krypton lamps from auction though, theyre rated 5kW CW though, so itll be tricky coaxing them into pulses without damaging the electrodes(I imagine at least). It'd be an engineering marvel, but I'd love to turn it into a small laser gun with either CW or pulsed operation available. Garage toys, am i right? 😅🤣
Congratz my dude! **highfive**
Very nice job. Congratulations.
I also started giggling like a schoolgirl when I got my first laser to work.
Your videos are very well made. I like that you get to see the whole process from start to finish.
Is it the same OC mirror as last time? 80% T?
Hey Andreas, Thanks for watching!
The OC for all the shots I filmed was a T=40%, I had switched it because I was afraid I was not getting enough feedback and that's why it wasn't working. In retrospect the T=80% mirror probably would have worked fine, maybe would have even given me a higher output power.
This is pretty neat! I'd be interested to see how the different laser optics you've shown behave and what their trade-offs are. Also, I'd be curious to see if this could be miniaturized by pumping the Nd:Glass rod through other means. I'm wondering if some high-power UV LEDs might do the trick, both due to their higher efficiency, and because controlling them should be much easier than tuning a pulse-forming network.
On that note, when you talked about how complicated tuning the pulse-forming network was, my mind immediately jumped to using a gradient descent algorithm to determine close-to-optimal parameters. If there's a criteria you can numerically evaluate for how "good" a pulse forming network is, a program can tweak all the other variables continuously to achieve something quite usable, even if the intial values you enter are complete bogus.
I have some experience with high-power, low-voltage circuit design, and also some experience with algorithms like the one I've described. I just lack the equipment to build a test rig myself right now 😅
Thanks for watching! There was a lot of experimentation that went into getting this thing to work including a lot of dead ends with different pump methods and control circuits. A lot of that I had to cut out so the vid wasn't an hour long, but maybe I'll make a write up/build log at some point in the future for those interested in the gory details :)
@@EricThornton24 Would definitely be an interesting read! I'm particularly interested in what other pumping methods you tried and how viable you think they would be. I'd love to experiment around with some of my ideas, but you probably know a great deal more on the subject than I do :)
@@upsidedownairline9388 you don't want to pump it with UV, you'll solarize the Nd glass and create F centers. Best pumping band is around 800nm IR. Probably need high power GaAs laser diodes to get enough irradiance to actually do it. This is the plan, basically anyway, for high rep rate lasers for an actual fusion reactor such as the HAPLS prototype at LLNL.
@@Muonium1 Thanks for the info! I was assuming UV LEDs would be best for this because they offer higher power densities, and didn't consider that UV might actually damage the crystal structure.
However, this further suggests that a flash lamp really is an inefficient way to pump an Nd:Glass laser, because electric arcs produce primarily UV light. I'm guessing the glass the flash tube is made of absorbs most of that to avoid damaging the rod?
@@upsidedownairline9388 the Xe Kr lamps have a fused quartz envelope doped with cerium or titanium to absorb the UV. The UV absorbing dopant actually makes them phosphorescent and the tube walls will glow blue for some time after the flash fires. The wallplug efficiency of the 30 kJ UV inertial confinement fusion laser I work on is literally 0.1%. The efficiency of IR diode pumped systems can be very high though, maybe 50%.
What will happen if you put some type of dpss crystall in laserbeam? There are lots of diffrent crystals.
Shouldn't the laser goggles be blue tinted given the pink rod? They need to be opposite of the laser wavelength emitted or am I wrong here?
I can sense your frustration and anger growing with each attempt. Until the the end. Lol
Thnx for ur effort what is the name of 2 black blocks that contan reflector mirror from where i can buy?
Hey, thanks for watching!
The mirror mounts I got (along with the rest of the optics for this project) from a Chinese company called "master laser". I think they may have gone out of business by now unfortunately, but the mirror mounts are a fairly bog standard part used in DIY CO2 laser cutters. Look around on the CNC side of Amazon/eBay and I'll bet you can find something similar...
Any other questions feel free to reach out.
-Eric
I've never been so scared of a screensaver in my life.
did I miss where you talked about the lamps, did you get new ones from this century, they look good
that is a crazy amount of electricity to be farting around with in your living room lol I got a 12 amp shock from my solar panels once, I seen angels for a second. I could hear the electricty powering up those capacitors from here lol
I STILL would not even be looking even with the glasses on, eye injuries are brutal, like movies pain for the rest of your life, it can happen accidentally at any time, cool videos, microscopically that laser OBLITERATED that razor blade, I bet it looked super cool with a super slow mo.
You can make second harmonic generation crystal
Neodimium in the tube, thats almost the same as the lenses in my didymium glassblowing specs
As usual I'm late to the party, thanks for posting including the setbacks. And of course congratulations, now if u will excuse me back to working on my world domination death laser. hehe u said 420 isn't math great.
Pulse portrait holograms
So you made an extrenal triggering circuit with flashlamp mounted inside aluminium made pump chamber. Are you going to use water for cooling purpose? I'm building my own laser now, so maybe we could share our thoughts and increase knowledge ;)
Hey, thanks for watching!
My trigger scheme is a bit idiosyncratic. Typically if you have a rod in a metal pump head like I have, you can just zap the whole thing with the high voltage pulse and that will trigger the lamp - no need to wrap the lamp in wire or insulate anything. But because I also made the mirror mounting plate out of metal, doing this would expose that whole plate plus the mirrors and related optics to the same pulse. When I tried to do this I couldn't contain the high voltage and things were arcing everywhere. Which is what led me to end up with the somewhat ridiculous setup of an insulated passthrough external trigger wire in an already metal pump head.
What would have been a much better design would have been to make the mirror plate out of plastic, or to account for some kind of insulation between the pump head and the metal mirror plate. This would have allowed me to use the pump head as the trigger wire and skip the whole nylon bolt passthrough.
The other option would have been to use series triggering (see the CalTech flashlamp pdf in the description of the video for more info) but that increases the cost and complexity of the whole circuit by a lot.
As far as cooling: for homebrew lasers like this with relatively low power outputs and low duty cycles, cooling (especially water cooling) is really not needed. The lamp does get hot, but even after 10 or 15 shots in a row as fast as I could charge the caps it was in no danger of melting and just opening the top of the pump head to let it passively cool was more than enough. With a larger laser (or a 3 level laser like ruby, which is less efficient) cooling might be necessary, but even then I would recommend forced air cooling over water cooling. The additional complexity and safety concerns brought about by pumping water through a metal chamber in close contact with lethally high voltage is not worth it IMO.
Best of luck with your laser - if you need any help don't hesitate to reach out, there is lot of neauence that I had to leave out of a short video...
-Eric
Thank you for answer!
About the laser - I decided to make something similar to lasers which are in commercial use. So I have to make not only trigger but also simmer circuit and of course water cooled pump chamber.
If you need high power supply for charging capacitor I reccomend variac and microwave oven transformer. It works pretty well (the same thing works with as simmer circuit).
Do you have some calculations for laser rod energies? How did you calculate output mirror transmission?
And also maybe it is just an impression but with so large Nd:glass rod you could use two lamps for pumping. For now it looks you didn't use whole potential of this rod. What do you think?
How did you get a NST like that without the potting?
It was an eBay score :) if you hunt around you can sometimes find them.
Hey Eric
I have an *** laser lying around, and you said I should get in touch! I'm being serious. Have this massive laser, and could use some info if you interested? Had it for a few years now, can't find any info on it, but it's itching for a rebuild.
🔥
I think it's already clear why the device didn't lase in the other video. You threw out the importance of aligning the rod to your reference laser. The rod creates the reference for the mirrors and other optics, so it must first be aligned to your reference laser. But the reference laser needs to be referenced to something, too, and I didn't see that it was. Ideally, you bounce the reference laser off two mirrors, creating a 180-degree turn, so you can easily align it to some reference in both near (first mirror) and far (second mirror) fields at the height of your baseplate that you want to have the beam be. Then, mount the rod/chamber and align both reflections, so they're on top. This is when you'll see if the rod surfaces are parallel to each other. Then, add the HR mirror and align the brightest reflection so it's on top of the rod reflection--there will be two reflections because you have two surfaces; the most brilliant is the first surface, closest to the rod. Finally, mount the OC mirror so its weak reflection overlaps the reference beam, and only adjust this mirror to get lasing started. If you do it this way and are very precise, you'll already be lasing, and only small adjustments to the OC are needed to make the beam circular.
If I look at the spot burned on the Zap-It paper--which is really overkill; one can use simple black copy paper just as easily--there is a misalignment in the vertical direction, and it's pretty serious. If you align, as I've mentioned, your power will be significantly increased.
:) Замечательный квантрон получился.
Very cool, glad you made it work. Also, I hate to be that guy, but two equal capacitors in series will double the max voltage, but it will halve the capacitance. Your total energy might only be a half of what you think you have.
Heya, thanks for watching!
You are absolutely right that when adding more caps in series the total capacitance goes down. In this case I needed the increased voltage to get my LC circuit equations to all work out. The total capacitance of this bank ended up being the same as in my previous attempts (580 uF), but because you get a V^2 in the energy equation the total energy of this bank was about 4 times as high! (420J vs 110J) Not a "high energy" laser by any stretch - but about the limit as to what i'm comfortable working with in the home shop, but certainly enough to achieve population inversion :).
круто, поздравляю, большая работа проделана, жду продолжения
Рад, что вам понравилось, спасибо за просмотр!
If the math comes out to 420, that's God's way of saying you have to light a bowl with it. I'd double up those goggles if you're gonna have your face that close to the laser though...
Ali express
Hello can you give the links to the things you used
First 🤪
shrimp????? ...i like it👍🏽🪬😁