Thoughts on eBay YAG?

http://cgi.ebay.com/ws/eBayISAPI.dl...Track=true&ssPageName=VIP:Watchlink:middle:us

Found this for <$200, if I sell either of my items I can afford it and I'm considering. Does it look good or is it a ripoff? What kind of power could I expect? mws? w?

Also, I know YAGs are pulsed lasers, but is it possible (read: in theory) to go CW on a yag?  just curious on that one.

you can make a yag CW, yag is the crystal you just have to find a lightsource capable of pumping they yag crystal sustained. Most yags are flashlamp or arclamp driven.

Honestly yags can be attractive for lots of power, buy they are hard to work with and I consider a 1064nm yag the most dangerous laser there is. a pulse from even a ssy1 like you posted is capable of 1-5kW ( 1-5000WATTS ) you can pout holes in metal with it, and it's invisible if you aren;t using a qswitch to go to SHG 532nm.

a fraction of the reflection will put a hole in your retina and you'll never know it. I know a guy who got a hole put through his glasses and a burn on the cheek from a BIG yag where it just barely nipped the edge of a mirror mount . He's damn lucky, he didn't even know what happened until it hurt and he checked to see WTH was wrong.

That is the common SSY-1 Nd:YAG laser head. For pulsed operation it's ready to go as is with the exception of the flashlamp circuit and trigger. As it stands it cannot be used for CW operation. You will have to tear it apart and get the 5mm x 60mm rod out of it. Pretty easy actually but then you need to build a pumping circuit for CW operation. This can be a krypton arc lamp or 808nm diode pump. Once you have the pumping system ready you will need a means of cooling it. The Nd:YAG rod in the SSY is considered heavily doped for CW operation. It's really designed for pulsed operation. Do you see how this will grow out of control very quickly? Every little aspect will have to be engineered for proper operation and safety.

Pulsed operation is measured in joules not watts but you can expect mJ out of it but it really depends on your design. I've heard of people getting some pretty good power out but they were not stock SSYs. I recently sold an Nd:YAG rod and mounts from a CW system that was putting out 35 WATTS! That'll leave a noticeable blind spot in your visual field, lol. Q-switches further complicate power output because the output pulse is shortened and the intensity is increased.

The circuits that power the flashlamp or arc lamp use voltages that will kill you outright. These lasers are not really for the layperson because you need to understand every aspect of laser operations.

What I'm wanting is a laser for metal processing/engraving. I'm torn between the YAG and the CO2. Both have the raw power to do it, but the YAG seems a LOT cheeper. Main difference in operation is the YAG is pulsed while the CO2 is CW. This means the CO2 coudl carve whole letters in one siting, while the YAG would pulse out dots that would form a letter. I could work with eitehr one, considering the system I'm workiong on uses a matrix for design.

I just dont know which would be better for the job...

Overall the CO2 is better for metal engraving because at 10600 nm it doesn't see most metals as reflective. Depending on what you are engraving the money you would spend on building up a YAG system from the ground could be better spent on purchasing a small CO2 engraving system.

Oh man, it sucks so bad that exporting the SSY1-Parts is not possible...Germany is no "Axis-of-Evil"-Country, and neither am I a terrorist

Hm, gotta find other ways

The SSY-1 laser is a well built small laser head. Mine has the dye cell Q switch installled and I've read on SAM's that in that configuration, I can reach PEAK power of near 1 MegaWatt !! I don't know if I believe this but the average power is quite low. They were built for range finders and the pulse out was ideal for that. I have made one shot pin holes in alum foil and observed the POP as air ionizes in front of a short focal length lens.

NOW-------
1 The flash lamp needs 450 to 900 volts plus trigger voltages in excess of 7,000 volts !
2 The output of 1064 nM is bad news for eyes. This is one laser for which I put on my laser defense goggles before the capacitor bank is charged.
3 I agree that CO2 run CW would be better for etching metal. However -- those use voltages in excess of 12,000 VDC ! The power supply will reach out and grab you.

So many lasers -- So little time

Mike

*jaw hits floor* a m-m-m-megawatt?!!?!?!? And this thing is portable?!!? (or, well, redily transportable) That's downright scary...

Ok, let me rephrase my question a bit... which is safer for somone who has read a lot about how to operate these lasers safely but has no experiance with it?

and my engraving system will consist of a small platform with 2 stepping motors which will move the object that shall be engraved around on an X-Y axis, controled by a PC, nothing particularily spectacular (and if possible I will wire the laser's trigger to the same software so it will know when to fire)

Ashton --

Remember, I said low average power. This won't go pow,pow, pow without cooling and that would be hard to do. The CO2 tubes just need flowing water.

I had to let my SSY cool after 5 shots in 2 minutes - -It gets warm.

We have a metal fabricator here in town with 2 CO2 cutters. 1,000 watt and 1,300 watt. 1/8" steel cuts like butter with the gas assist.

Mike