ND:YAG rod dopping

[RickLaser]

Hi all,

i work with Co2 laser since 1980, now i want assemble a nd:yag laser, the point is, i read many posts about ways to pumping yag rod but nobody talk about dopant % of rods . At ebay u can find alot of rods with 0.6 % , 0.9% neodimium but that low dopping is used only to CW pumped with arc lamp, and arc lamp drive is so expencive. i found some posts at phisycian pages saing that to pump yag with flashlamp a hight dopant lever is needed like 3%. I wanna know if some of u guys have some REAL experience with yag pumping and if a cheap 0.9% rod work with flashlamp. Please post any experience with every kind of pumping and % dopant.

 

[Things]

You're probably better off asking this over at Photonlexicon.com , I don't think many people here have dealt with Nd:YAG lasers.

 

[Meatball]

As a general rule, the shorter the pulse, the higher the system peak power, and the higher energy the pump is, the lower the concentration is what is typically seen.

You must choose this dopant level based on what you are trying to optimize - what are your needs? What is your priority?

For most q-switched systems, you'll see rods from .5% to 1.5% depending on pump pulse length. For no q-switch or quasi CW (not recommended with YAG), lower concentrations will be typically found. Something from .05% to .5%.

Let it depend on this following parameters:

beam beam diameter after output coupler
rod length
pumping scheme (diode, lamp)
pump energy/power
pump arrangement - side pumped? End pumped? Q-switched? Pumping chamber?
if q - switched, passively? Opto-acoustically?
pump pulse duration
YAG beam pulse length
duty cycle

But honestly, if you're just trying to muck around with a rod to get something to lase, you'll probably seen something interesting out of it before you begin to miss your chance to change your mind. You'll get something out of a proper rod. You should instead find a nice rod, and design your system around it. Optimize your laser towards whatever the rod can offer you.