I want to build a laser

[Zippiot]

I have been studying the subject for the last week and I think it can be done...but there are a few things I need answered.

 

For a metal vapor laser, can it be run on zinc with a co2 buffer gas?

For a nitrogen laser, having trouble understanding the power supply/spark gap system...

HeNe laser, will other inert gasses in a sealed tube strapped to a tesla coil lase?

 

And also what kinds of power sources can be made to produce the listed laser types?

 

My understanding of electronics isn't very vast but I am learning

[learnin to learn]

yes lasers can be made! my knowledge on this subject is limited, do a google search on laser projects! I know that the army has many laser projects and so does some other private companies. If you are still interested in building a laser after you have read up on them a little more, I suggest you start saving some money!

[Zippiot]

It looks like a solid state laser can be made using halogen bulbs...wonder what crystals are useable with a halogen bulb?

I have easy access to Quartz and Halite, but there is no way I would pay the thousands for a ruby rod or nd:yag

 

Having trouble understanding some of the electronics diagrams, does anybody have a site that explains what each symbol means?

[cwes99_03]

Which symbols are you struggling with?

Most can be easily found in an introductory electronics book.

 

But I suppose I will do the work for you.

 

Start like this.

 

http://www.google.com/search?hl=en&q=electronics+diagrams+explained

 

Then when you see any particular words repeated over and over like the word "circuit" in the above google search, you learn to modify your search.

 

http://www.google.com/search?hl=en&lr=&q=circuit+diagrams+explained

 

Then maybe you focus in on one part of a circuit diagram to learn about it

 

http://www.google.com/search?hl=en&lr=&q=circuit+diagram+tank+circuit

[Zippiot]

Thanks, a bunch of google searches alter I have compiled a few sites that cover all of the symbols I see repeated. Too bad it seems each person uses a little modification occasionally, but most of the symbols stay the same.

 

To radioshack! Anyone know how to rig a circuit to use the little halogen bulbs they sell? Don't know the wattage of them, just want to rig 3-6 of them to one power source...

[cwes99_03]

Generally the packaging will tell you the power requirements. Then it is a matter of adding resistors into the mix if needed. I know some LED's need to be in series with a resistor and in parallel with others for them to produce light.

If you don't have the electronics experience I suggest the following.

 

1) Buy yourself a bread board or two (with digital power supplies), a half dozen different types (sizes) of resistors (10 of each), some capacitors (various sizes, 2 or 3 each), some inductors (just one each of two or three different sizes), some diodes (again just one each of two or three sizes), some LEDs (sizes and colors just for fun), three spools of 18 gage insulated wire (black, white, and red), $10 pair of wire cutters/strippers, 1 pair of side cutters, a good sodering iron (i would get the instant hot/instant cool cordless type), and a $15 multi-meter. You can also use power supplies ripped out of old computers. They are great for providing digital quality voltages. You could try to remove some resistors and whatnot from old useless computers too, but I'd stick to buying some, they are pretty cheap.

 

Edit: Batteries will work in place of power supplies, and may be safer for the unsupervised beginner. Of course you can have fun creating a battery too with tin foil and vinegar.

 

Anything I've left out?

 

2) get online and find yourself some introductory electronics labs that will teach you about wiring things in parallel and series, or maybe a cheap introductory book that contains labs.

The experience will be invaluable and will only take a month or two of playing.

Then you can graduate to a couple of switches, gates, and other motorola chips to learn about digital. Of course, digital chips are most fun when you have some wave generators and an oscilloscope too, but these are gonna cost you a bit more.

[Zippiot]

I have all the tools and have been soldering together stuff for years now (I am pretty good too) but knowing how to attatch a resistor in series is much different from know what type and wattage resistor is needed...

 

I know how to attatch stuff just dont know what to attatch :P

 

My friend was helping me (he is an electronics engineering student at northeastern) but has since changed majors and can no longer offer his help; which turns out was just him asking his professor...!

 

I am scrambling all over the internet and have been reviewing my findings with many just to make sure that something doesn't explode, I am sick of stuff exploding!!!

 

watts=volts*amps, so a 120v outlet that makes 15 amps needs to go through a resistor before it can be attatched to a 250 watt halogen. My question is what type of resistance would be best, there are many types of resistors and many ratings. I am sure the back of the bulb will tell its tolerances, I'll work from there.

[Zippiot]

Stuff is starting to come together!

 

Lets say I want to make a halogen pumped solid state laser with a quartz crystal as the lasing medium. I found a site that says that glass can be lased for about 10 seconds before it needs cooling, quartz is like super glass when it comes to heat. So it is proven that glass can be lased (and quartz and glass are both SiO2) with a pulsing flashlamp. A halogen will produce much less power, but that is not a problem if it lases at all it is a success!

For the mirrored surfaces I was thinking the highly reflactive part can be polished aluminum/silvered aluminum and the slightly reflective surface can be quartz/glass (has a natural refleiveness of 4-10%) or halite (don't know reflectiveness). Enclosed in an aluminum pipe I have to keep some of the light energy from being wasted with a polished washer at the front end (the aluminum reflector will make up the rear of the pipe) the washer will reflect some light back into the tube and restrict the size of the beam coming out. The washer will be drilled to fit the quartz rod...why not just use another polished piece of aluminum with a hole in the middle instead of the washer? Sounds good!

 

Now all it needs is the proper power supply (which it doesn't look to be so bad if I use 250 watt halogens) and to create some cooling. Mineral oil filling the aluminum pipe sound ok? It is clear so the light will pass freely and it will keep stuff cool, also may transfer heat away from the bulbs and lasing medium and bring it to the aluminum shell.

[cwes99_03]

Kaboom! Cause the halogen doesn't like being in contact with liquids.

[Zippiot]

See that is why I am here, to have people tell me when stuff will EXPLODE!!!!!!!

So high volume air cooling is necessary then. That is pretty simple at least, I have a few blowers

[cwes99_03]

I can't say that for certain, but think of an ultra hot lightbulb coming in contact with a liquid. The glass is thin to save money on manufacturing, and superhot glass in contact with cooler liquid will cause the glass to fracture.

Air doesn't do this because an air pocket forms around the glass that is easily heated and cooled.

 

Not to mention that submerging your light source and crystal in a liquid makes for all kinds of new lensing (difraction) problems.

[Zippiot]

To be fair, the bulbs are made of quartz not standard glass...quartz has much better heat and cooling ratios over glass. Many quartz tubes can be heated to over 900 degrees then dipped in 20 degree © water for 20 seconds with no fracturing or cracking.

 

Got that from a website that made quartz tubing, that stuff is expensive

[TheBigDog]

Welcome to Hypography Zippiot!

 

When I was a kid I had a friend who's dad was an engineer for Spectra Physics in the laser department. This was in the late 70's, early 80's and lasers were not common place yet. But they always had a few at the house that we could play with. I rememeber him taking a group of us kids to his work and showing us how they built and experimented with the lasers. Including how they were fabricated. At the time they had just patened the first supermarket barcode scanner and business was booming.

 

Making a low power laser can be done with cheap parts and some can-do spirit. I would start with something small, and then work your way up. The ones that we saw were chemical. It was a tube filled with gas that would illuminate when charged. At one end of the tube was an opening that had a mirror that reflected 50% of the light back into the tube, and let 50% of the light escape. At the other end of the tube was another mirror aligned exactly opposite the first, but with 100% reflection. When you turned it on photons would be going in all directions inside the tube, but the ones that started bouncing back and forth between the two mirrors would let the point of light escape out. There was a bit more to it than that, but generally speaking that was how it worked.

 

As you progress on your project post pictures so we can follow along!

 

Bill

[Zippiot]

Right now I am in the design phase, trying to decide on exactly which laser to build. With the tools I have it seems a solid state would be easiest, as my forge can grow its own crystals (but I doubt they are any good...). After that would be a simple gas laser, nitrogen lasers are super easy and produce good results but they are finiky, bulky and not very powerful...Other gas lasers are CO2 (which sounds like what you described) and non dangerous HeNe types. Those are pretty much neon signs with mirrors.

 

I have a neon sign power supply, this might affect my decision but for the moment, a solid state laser looks like the right way to go for simplicity.

 

Also metal vapor lasers interest me, seems pretty simple but I am sur eit isnt.

[GAHD]

Keep in mind your mirrors need to be alligned very well. An 80%-98% reflective mirror is best for the output component as it will give a brighter beam.

[Zippiot]

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

How hot does a gas laser get, like if I wanted to test the principle of my design could it be built of pvc pipe and run for like 5 seconds? Want to do it with something cheap before I try to use expensive tubes of glass or quartz.

 

 

I have a neat idea, might be able to make the thing out of acrylic (or glass if I can manage to piece together a glass box), I will try my best to describe it.

 

....deleted this description too hard without a pic....

 

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?

[Zippiot]

 

The electricity arcs accross each bridge, exciting the gas filling the chamber. Should produce some light, if I can concentrate it by the mirrors then It just might lase!