Nd: YAG Laser Help

[Moto154]

I'm looking to start a project building a YAG laser. I do not know a few things though: what percent transmission output mirror to use, distance of the mirrors from the rod, size of flash lamp needed, and any information about the circuit needed to create the pulse (not looking to have pulses one after another but single pulses with a flip of a switch). I am looking to use a small rod like this 1 pc Nd-YAG laser rod 3 mm x 50 mm USSR NEW! | eBay Any help will be greatly appreciated

 

[diachi]

What sort of experience do you have with lamp pumped solid state lasers? Have you ever worked on one before? Why do you want to build one? Do you have experience with high voltage/energy electronics?

 

[Moto154]

I have little experience with this. I am interested in building a lamp pumped solid state laser to strengthen my experience and understanding of these methods and concepts. I will be majoring in physics with a concentration of electro-optics in the fall.

 

[paul1598419]

This is a highly dangerous and not particularly efficient way to pump a YAG. Have you thought of diode pumping it? It would probably be cheaper and you could do CW and the efficiency would be better also. Less chance of killing yourself too.

 

[Cyparagon]

I will be majoring in physics with a concentration of electro-optics in the fall.

That means you have much more access to learning resources than we do. Have you tried the library, professors, or a scientific journal database search of some kind?

The answer to your question depends on many things, like the pump energy, the desired pulse length, the doping percent, and several other things I'm forgetting, no doubt.

 

[Moto154]

My last day of high school is next Tuesday so I won't be in college until the fall. I know it's dangerous. When doing this I will have safety at the top of priority list. I'm looking to use a fairly small rod and I'm not looking to get very high output power; I'd imagine this would be a little safer. I read somewhere the flash lamps from disposable cameras could even be used for pumping, so this is a possibility (I also am aware the capacitors in disposable cameras have a dangerous amount of voltage). The idea of pumping with a diode is good however I want to pump with a flash lamp for a better understanding of these concepts. I don't know the doping percent of the rods I linked above :/. I guess I could go about this by experimenting with settings and things to see what works best. Another thing I'm unsure about is the transmittance of the output mirror, but I am thinking 70-90% (read from a website). Has anyone tried using flash lamps from disposable cameras to pump an Nd: YAG rod?

 

[diachi]

My last day of high school is next Tuesday so I won't be in college until the fall. I know it's dangerous.

When doing this I will have safety at the top of priority list.

You'll need safety glasses for 1064nm and HV electrical safety experience at the least.

I'm looking to use a fairly small rod and I'm not looking to get very high output power; I'd imagine this would be a little safer.

Define "not looking to get very high output power". A flashlamp pumped Nd:YAG (even a small one), even at fairly low energies, has a short pulse duration and thus a high peak output power, easily in the kW range. That's a matter of physics that can't be changed.

I read somewhere the flash lamps from disposable cameras could even be used for pumping, so this is a possibility (I also am aware the capacitors in disposable cameras have a dangerous amount of voltage).

Don't see why it wouldn't work, but proper lamps/capacitors/pulse forming networks/triggering will yield better results.

The idea of pumping with a diode is good however I want to pump with a flash lamp for a better understanding of these concepts. I don't know the doping percent of the rods I linked above :/.

Dopant percentage is important, you need specific dopant percentages for diode/arc pumping (CW) vs flash-lamp pumping (pulsed). Not that it won't work with the incorrect dopant percentage, but results won't be optimal.

I guess I could go about this by experimenting with settings and things to see what works best.

Another thing I'm unsure about is the transmittance of the output mirror, but I am thinking 70-90% (read from a website).

That'll vary based on the overall design of your system and your requirements. Keep in mind they're not just plain old silvered mirrors, they need to be specifically coated for your chosen wavelength. Other things need to be taken into account. Cavity length? Mirror configuration (planar, confocal etc)?

Has anyone tried using flash lamps from disposable cameras to pump an Nd: YAG rod?

See replies in red.

I'd recommend doing more reading before starting this project, on laser fundamentals as well as solid state laser construction/theory. It would certainly be an interesting project, but from the sounds of things you aren't quite ready to begin the construction phase... Do lots of reading/research first. Even small flashlamp pumped Nd:YAG lasers are dangerous, with voltages and energies that are more than enough to kill. Never mind the optical hazards and anything else I may be forgetting...

Sam's Laser FAQ has a good section on home-built solid state lasers.

 

[Moto154]

diachi, thank you for the reply, very helpful. I know styropyro made a video building a pistol YAG with a pre-built YAG head; this seemed to have an output I'd be satisfied with. I'm sure his YAG pistol output a lot more power than it seemed considering it's pulsed. I definitely need to do more research and gain more experience before I start this project, might be better to try after being in college for a bit. I've seen a lot of rods around 40mm for pretty cheap but haven't seen any doping percentage specs along with them. Planar mirrors seem to be easier to obtain and I'm assuming are cheapest. Perhaps I'll get lucky and find one with proper specs eventually.

 

[paul1598419]

Oh, I see you are still in high school. You are far from learning anything in college that will help you with this project. Think in terms of your junior year. And that would be if you are going for a physics or engineering degree. You have much to learn before you even consider tackling this project.