Mods - please move if you deem apropriate, I wasn’t sure if this is the best forum or not, but it is a question.
I want a laser. Preferebly something smallish and handheld. Something like a laser pointer but instead of just a low power light where it points, I want it to actually burn and/or cut. I would prefer something that is ready made, but I am capable of building something if its not too difficult (like soldering and such). I am not going to go around shooting people with it (it wouldn’t be a weapon or anything). I just think it would be neat to have. I am sure I could come up with some practiacal uses…just don’t ask me now.
You can buy lasers at Edmund Scientific, or American Science and Engineering, or at any of a number of companies. The ones Edmunds sells are either low-power HeNe lasers (in three colors) or laser pointers (either red or a more expensive green). None of these is going to cut through anything that looks at all impressive.
As I’ve remarked in an earlier thread, hand-held laser devices have a problem with waste heat. You MIGHT be able to build your own laser with a custom cooling supply, but by your own admission, that’s not your forte.
For the record, ruby lasers, Nd:YAG and Nd:glass (and other varieties of neodymium ion laser) can be made small enough to carry by hand, yet blow holes in things (although you’ll still need an umbilical hooked up to a power supply and cooling supply). You’ll probably want to mode-lock and/or Q-switch the laser to get a pulse with a lot of oomph, so your laser will put out a pulse or pulses, not a continuous beam. Not only will this be cumbersome, it will not be cheap. It would be cheaper and easier to carry a propane torch.
Go pick up an issue of popular science or popular mechanics.
Flip to the very back.
There is at least one company in there which sells lasers.
I’m not sure they are high powered enough for your purposes though. What do you want them to be able to burn or cut?
(I keep thinking the company’s named something like scientific american or such, but that really doesn’t seem right. The company I’m thinking of does have a web presence and sells all sorts of fun scientific gagets, I may have them bookmarked on my home machine, if so I’ll drop you another response.)
I have a collection of books and articles on building your own laser. I don’t know if they’re still in print, but I have two books for the home enthusiast. One is from TAB books (they publish electronics books). It gives instructions on building HeNe lasers, semiconductor diode lasers, and a ruby laser. Only the ruby laser seems likely to do the kind of damage you want to do. Charles Townes (I think) had a ruby laser built into the plastic housing of a toy ray gun. He used to use it for demonstrations, the most impressive being the one where he’d fire the laser through a transparent balloon and break a colored balloon inside it, without damaging the clear balloon.
The other book is from Scientific American, and is a series of reprints from their “Amateur Scientist” column. If you can’t get the book, you can at least go to the library and copy these pages from old issues of SA. They tell you how to build a HeNe laser, a Nitrogen laser, and a semiconductor diode laser. These, again, won’t let you do much mayhem. But they also give instructions for a carbon dioxide laser and a general gas laser, and you can get some serious power out of those.
If you do plan to follow this path, then be EXTREMELY careful with the required high voltages (for the CO2 laser you have to get your hands on a neon sign transformer). Also be very careful with the laser beams themselves. Go to the library and scan one of the texts on laser safety, such as the CRC Laser Safety Handbook. Edmund Scientific sells laser protection goggles that might be worth your while. Remember: laser beams that nmight not do an impressive job on a piece of paper can do a LOT of damage to your eye.
If you want to be able to burn stuff you need an industrial or surgical laser,and even used, neither is cheap. Once upon a time, somehow, I ended up on a mailing list for a company that sold all sorts of used industrial equipment, lasers among them. They had the lower-powered light-show stuff as well as welding and cutting equiment. They give the technical specs, most of which I didn’t understand - they don’t have any easy rating system for what kinda stuff you can burn, but heck, I like burning stuff as much as the next guy. I started reading the fine print of the listings.
-One I remember was originally used for cutting 1/4" steel. I can’t remember the brand name, but I recall that the output was 10 watts. The laser itself was inside a small cabinet about 1 x 1 x 3 feet. That hooked with a few thick cables to another cabinet, about as large as a good-sized refridgerator. That cabinet hooked to two other cabinets the same size as it with a bunch of cables, and each of those hooked to a couple cabinets each about 4 x 4 x 4 feet. I can’t remember what kinda power you needed for it all, but I’d bet it don’t plug into a regular wall socket. The laser had “about 10 hours left before rebuild” -that is, about ten hours of operational time left. (High-power lasers have definite lifetimes, and they aren’t real long. Many can be rebuilt, but that’s not a minor expense.) The asking price on this sweet little rig: $75,000 USD.
-I also saw a surgical laser of a couple of watts, that they mentioned was usable for burning and cutting. Burning and cutting what besides flesh I don’t know, they didn’t elaborate. I’d guess if you understood the power output characteristics you could figure that out for yourself. It was the full surgery-room setup, mounted on a boom arm, just like you see on E.R. It was priced at $35,000.
You could build a CO2 laser. The main expense there is a neon sign transformer, which is around $100. Maybe someone else can chime in about how to make one, or at least how they work.
See my post above. The Sci Am article gives you directions for building the whole shebang, right down to cutting the copper mirrors. You’d better either be dedicated, or willing to shell out bucks for special components like dielectric coated mirrors. And with the gas supply required, this will NOT be very transportable.
About ten years agoI worked for a resistor manufacturer. One of my duties was to set up the lasers when they changed sizes. We made 1/4 watt up to 2 watts IIRC metal film resistors.
The laser cut through the metal film(thin film) that was deposited on a ceramic cylinder.
The laser itself was about 6 inches long but the accompaning mirrors for focusing the light was about 4’long and about 1 ft square. The power supply had its own refrigeration unit that circulated coolant. That was about the size of a three drawer filing cabinet.
Several times I inadvertantly had a finger" burnt".The pain was about like almost pricking your finger. No real pain just enough feeling to know something happened.
If the laser wasn’t focused properly it wouldn’t even burn the film
I would guess you are going to wait a couple of decades before you carry around a laser weapon…
If you ant something to build, then investigate larger-diameter gas lasers that you can then focus with a suitable lens. IIRC, the lens has to be made of quartz (another part not cheap) but overall the whole thing costs a lot less.
Edmund Scientific also sells glass tubes that I understand are suitable for smaller D-I-Y gas lasers. They are high-precision quartz-glass pieces with the ends squared, which is what you need to start with. Not cheap. ~ I once ran across plans to build a gas-discharge laser and it really didn’t look that hard to do, just expensive: several hundred dollars at the cheapest. It seems if you wan to build a laser, there’s some parts you can’t easily make that are only used for lasers, that aren’t used for anything else, and aren’t cheap. - MC
Most people that want to cut things with a laser do it with a carbon dioxide laser. Lots of industrial componies sell 'em. But be prepared to spend thousands.
