Covert 808nm to 532nm HELP!

[mixedgas]

Thanks for help. I did as you said but there no result.
There is some way to check if the Laser diode works at 808nm and also to check if the crystals are not broken?

Do you have another laser you can use as a master laser to do a mirror and crystal alignment?

Do you have safety goggles for 808 nm?

Steve

[AlexGe]

Hello MIXEDGAS!
I have another green laser but it is not C-Mount an allso a small red laser.
No, I don`t have a safety goggles.

[allthatwhichis]

No, I don`t have a safety goggles.

Then PLEASE stop working with the non-visible 1 watt(ish) laser until you can buy a pair. Please! I can bet they will be flying off the dusty shelves of some of the members here just for you.

[AlexGe]

Thank you .....

[SideFX]

heya..

sorry for digging up an old thread, I have exactly the same laser which needed to be repaired.. it wasn't putting out more then 40mW of 532...
I purchased a 2W 808nm C-mount diode from snoctony, and carefully placed it in the module.
After some fiddling a got some green out of it. I learned that the crystals/mirrors at the far ends are hard to align.. espacially with this type of module. It's impossible to re-angle the output coupler.. other then stuffing pieces of paper underneath I had to loosen it and move it around, but that gave me the necessary green flashes from which i went on.


After a few days fooling around, I was able to get around 100mW of green, driving the diode at 2A. I can't drive it up to the full 2.8A as my driver won't go any further.. So is this an acceptable power at this current..? Or should i spend some more days at this?

[ElektroFreak]

100mW@2A is a tad low, but not by too horribly much. With a properly aligned cavity, 2A into a 2W diode should get you around 150-175mW of green. I wouldn't run the diode at the full 2.8A personally, since underdriving it will give it a VERY long life, so I wouldn't worry about your driver not being able to supply it. 2A into a 2W should be about perfect for longevity.

You might be able to squeeze a bit more power with more fiddling, but it depends on whether or not it's worth it to you. If you're getting 100mW with a nice clean stable beam, it might not hurt to just leave it be.

[GooeyGus]

yeah you should be able to get a bit more. I had a 532nm laser that would do over 300mW with only about 1.3W of pump power. Also, I had another laser that did 200mW with only 800mA to the pump diode, so you should be able to get quite a bit with 2A of pump. I think even the 1W greens only use ~3.5W of pump.

Now that your output coupler is at least aligned well enough to lase, try tweaking the KTP a bit to see if you can increase the output. If not, trying changing the alignment of the lasing crystal (the one nearest the pump diode) to the diode. Pump diode alignment is also critical for peak power, but not quite as critical as mirror alignment. Turn the power down to around 1A and see if you can get it back up to 100mW, then increase current from there.

EDIT: forgot to add... it's possible that the original diode is a bit different from the snoctony diode, depending on the FAC lens installed on the diode. It is quite possible that you will need to move the diode a bit closer to the crystal, or a bit further away (if there are optics after the pump. If there are no optics after the pump, just get the diode as close as possible to the crystal)

[ElektroFreak]

By my reckoning, 2A into a 2W diode that normally runs at 2.8A should only yield around 1.3-1.5W of output. Every 150mW class DPSS I've seen uses 1.2-1.5W pump to obtain 150-200mW.. What were the ratings on the diodes you were using in those cases, gooey?

[oliverst14@hotmail.com]

iv been pretty interested in this for a while now. how much work is involved in taking a 300mw green laser apart that is broke and and installing an 808nm diodes that can be capable of doing 10watt. im guessing this would work in practice but the components would fail due to them not being rated that high as well as casing getting too hot. just wondering thats all.

[ElektroFreak]

You're correct. It wouldn't work due to the reasons you state. One of the causes of failure would be coating failure on the crystals and optics, and might also include physical damage to the crystals themselves from the fact that the incident pump energy will have to be many times stronger than the crystals are deigned for.