Thanks very much! I am not entirely sure what caused the faint rings to appear. If I had to guess, I would say it was probably atmospheric thermoclines. As the laser light passed through different layers of high pressure, moist air, and low pressure, dry air, varying levels of laser light were scattered from the beam. Just a guess though, could also just be a lens effect...
I bought my IR, C-Mount Diodes from eBay. The ND:YAG resonator I was able to purchase from a site called O-Like. They sell completed modules, but I wanted to build my own. You can also buy driver circuits, and lenses from O-Like. I made my first driver circuit, but O-Like's drivers are better... If I recall correctly, this one cost me a little less than $300 to build, but the price of c-mount diodes has gone down significantly since I made this one! Let my know if you decide to build one! Laser Forums [link] has a lot of info from fanatic buyers, and builders; so what ever you decide to do, lots of good advice to be found there! (If you can handle all the Star-Wars talk... )
You may have answered this already in the comment threads, but I'll ask anyway - What caused the concentric halos around the center of the star?
And as a material science grad - Is your laser rig from off the shelf parts, and about how much did it cost...?
I bought my IR, C-Mount Diodes from eBay. The ND:YAG resonator I was able to purchase from a site called O-Like. They sell completed modules, but I wanted to build my own. You can also buy driver circuits, and lenses from O-Like. I made my first driver circuit, but O-Like's drivers are better... If I recall correctly, this one cost me a little less than $300 to build, but the price of c-mount diodes has gone down significantly since I made this one! Let my know if you decide to build one! Laser Forums [link] has a lot of info from fanatic buyers, and builders; so what ever you decide to do, lots of good advice to be found there! (If you can handle all the Star-Wars talk...