473 crystal question

[wolfhunter9154]

Is there any way to test/repair it? From what I can tell, it goes straight into the cavity.

 

[Meatball]

Mount a TEC on the top on the crystal assembly. Ignore the set on the bottom, and rewire the driver to the new TEC. Use thermal paste and a small heatsink, and maybe it will all still fit inside the enclosure. This is assuming temperature is the problem.

The LBO crystal is not necessarily supposed to be cooled though. Play with different current settings on the TEC to find a point where the 473 comes out in tip top shape. A heated crystal can still be more easily phase matched than a cool one in some situations.

It will come down to many variables, so just goof around with the alignment, turn some pots, and see what happens. Thats what you bought it for, now get to playing with it!

 

[wolfhunter9154]

Ok. Thanks for the help everybody! Ill try this tomorrow. Right now, Im going to bed.

 

[qumefox]

If the thermocouple is the problem, changing TEC's isn't going to help. But I agree. Play with it. It's the reason I have five heh. And also because your not going to find a better deal on the collective parts these have in them. I plan to convert one to a 532nm. And I sacrificed one trying to make my 589 GPL lase again.

Mount a TEC on the top on the crystal assembly. Ignore the set on the bottom, and rewire the driver to the new TEC. Use thermal paste and a small heatsink, and maybe it will all still fit inside the enclosure. This is assuming temperature is the problem.

The LBO crystal is not necessarily supposed to be cooled though. Play with different current settings on the TEC to find a point where the 473 comes out in tip top shape. A heated crystal can still be more easily phase matched than a cool one in some situations.

It will come down to many variables, so just goof around with the alignment, turn some pots, and see what happens. Thats what you bought it for, now get to playing with it!

 

[wolfhunter9154]

Were you successful with your 589?

 

[qumefox]

Sadly no. I think the reason it quit is because the cavity alignment screwed. I haven't given up on it completely though, and when I get time I plan to move the gain and doubler crystals, as well as the OC to the 473 cavity and attempt it again instead of trying to keep the cavity out of the GPL intact like I did on the last attempt.

 

[Deleted member 16589]

:cryyy::cryyy::cryyy: I cant find my photos i know i took some before i gutted it lemme keep looking I hope I find them
otherwise ill just post new pics of the gutted remains LOL

I would like to see pics of this 473nm head. I have five of them and they've all been identical to the OP's picture. With the cmount pumps these use, I don't really see how your setup would be able to focus the pump well enough to even lase.

Wolf, If your crystal assembly is getting warm, then either the TEC is dead, the driver for it isn't working, or there's a bad connection somewhere.

Also, no, the crystals aren't 'glued down' at least not in a fashion they aren't adjustable. the OC has adjustments, and the doubling crystal mount will move side to side and front to back if you loosen the screws and break the epoxy. These are FAR more adjustable than any cheap 532nm pointer you'll run across. I've had one of mine completely dismantled, and the doubling crystal completely out of it and I managed to make it work as well as it was originally when I was done. I don't advise playing with the OC alignment though. If you screw that up and lose your intracavity 1064nm, your pretty much screwed.

 

[Meatball]

Sadly no. I think the reason it quit is because the cavity alignment screwed. I haven't given up on it completely though, and when I get time I plan to move the gain and doubler crystals, as well as the OC to the 473 cavity and attempt it again instead of trying to keep the cavity out of the GPL intact like I did on the last attempt.

^^
The LBO optic used in your 473s and 589s needs to be kept sealed up from open air while their not in use. It can only a take a couple of weeks before they absorb enough moisture from the air that they become unusable.

 

[qumefox]

They are. They're sealed in bags with silica gel currently. Though that might have been the problem with my GLP 589 to begin with. And why aryntha's GLP died from just sitting.

 

[wolfhunter9154]

So I took the the cavity out today, and the part that contacts the base of the module, gets cold. So I reversed the leads on the Peltier cooler, and it is much brighter and it holds steady! Once again, thanks for the help everybody! For about 40 dollars, I'm happy with just switching some leads!

 

[qumefox]

That's awesome. Though one wonders how the peltier got wired backwards and no one caught it. These heads were made by CNI (just have B&W tech branding and drivers). You'd think something like that wouldn't make it past QC. Either B&W's or CNI's.

 

[wolfhunter9154]

Yeah I was wondering about QC. Like I said, I will test it more tomorrow, but from what I saw, it is holding strong and steady.

 

[Wolfman29]

Yeah - the base of mine gets nice and warm. That's how I know it's working!