Melles Griot 561nm Lab laser

[ultimatekaiser]

Just a plug. I'm going to wire a standard plug to it so it's nice and tidy. Rather than just sticking the wire down a cable slot. That and I gotta check to see if I have any 12 gauge wire left.

 

[Sigurthr]

Honestly you could use up to 18ga without any trouble. It wouldn't pass inspection, but you wouldn't see any significant thermal effects either.

Keep in mind the driver and head are meant to be mounted to a HUGE heatsink (optical table) so if you run them for long periods on insulative surfaces you may see degradation of performance.

 

[ultimatekaiser]

Yeah I know. I've worked in an optical lab before. I have three near my house. There are some fun goodies in one of them including a Ti:sapphire which's got a 30W 532nm pump. Not a toy.... though it's got some damage and needs a new crystal. It's got a bunch of grey tracking. We keep having to move the Crystal around to use a new spot-it's quite frustrating.

 

[Sigurthr]

It's still a toy, haha, you just don't use it as such. Never lose sight of the joy of such things, even if you have to bury it to save face and get work done, remember to acknowledge it when you can.

30W 532, eh? Geez, I wonder what's pumping that... a 200W bar array?! Probably more likely a flashlamp for the Nd:Yag.

 

[ultimatekaiser]

Haha I was joking around, that's why I smiled when I said that sorry it didn't come across well. It's a special YAG cavity but I'm not positive, as I've never asked/looked inside. I think it is a dual frequency locked diode array pumping a rod. Looking at the power requirements might tell me without opening it. Honestly it's a fun laser, but overly complex. And not much I use it for. I just enjoy seeing it running. It's cool to see. But owning one would be a complex hassle.

 

[bdgreenb]

UK! when is this baby gonna be up and running?

 

[ultimatekaiser]

I should have it done by the end of the week if all goes well. I might stream its first photons to the forum on Skype if I'm asked nice... we can all welcome it to the forum together

 

[ultimatekaiser]

OK! It lives! sorta....

I got it to fire up tonight with no problems, it works...but it only runs locked at 5mW? perhaps because it doesn't have the matching driver?

connecting to the head I issued a LASOW:REF? command and it spat out 10.5
however I cannot change this setting or the current setting, not high nor low. it always gives me an error 103. basically that it's password protected. fine and dandy...but then why is it not putting out the power it's supposed to? I'm not quite sure what to make of it. and something tells me MG won't help me...

Update: now it's only doing 3mW this morning and the beam is slightly multimode. Something's definitely not right.

 

[ultimatekaiser]

Well it's improved a little beam wise and now it's back up to 5-5.5mW hmmm

 

[Sigurthr]

Hmm, I hate digital electronics mixing with lasers, lol. Glad you're able to get it running at all. It's too nice of a unit to hack, unfortunately (lol, that is odd to say- "this thing is too nice, damnit!") else I'd say screw the digitized front end and manually run it on good old analog electronics.

 

[ultimatekaiser]

I've done that before, but I'm not sure if want to with this... But it is nice. It seems to like maintaining about 5-5.5 mW for quite a while, but not mounted to a breadboard it eventually "overheats" (baseplate temp error). Restarting it runs it at a low power. So it must be thermally controlled, and I'm betting the reported temps are off since it's not the matched driver.

 

[Sigurthr]

I had similar problems with a 80mW (10mW rated) 473nm head I had a while back. There, I disabled the optical feedback and changed the thermal feedback to always read as optimal conditions (so a steady state would be reached), then realigned the entire laser until it preferred to run at the temperature which the head would reach equilibrium at when not mounted to a large heatsink (which I remember being something around 115F). It turned out well as the previous owner could only get 21mW out of it and I quadrupled that, and it stayed stable for dozens of hours of use with my modifications. I later sold it off and the new owner had no issues.

The difference was, it was no where near as pretty or valuable of a laser as the one in this thread. I'm not sure how you should proceed.

 

[DashApple]

lovely laser , Hope you get it sorted ,

I do like the RS232 controlled systems , nightmare when they do go wrong but love em when they work

I had fun trying to get my laser quantum gem to run , was funny that it could be tricked into doing over its specked power , but I never tried it myself .

 

[Sigurthr]

Hrmm, it is possible that the near TEM00 mode is resultant of the pump running at under optimum current. I've seen that before in SHG systems. Are you able to open up the head and trace the pins to manually determine pinout? (a nightmare, I know!)

Only thing else I can think of is to shoot an email off to Sam Goldwasser and ask for his input.

 

[ultimatekaiser]

Hrmm, it is possible that the near TEM00 mode is resultant of the pump running at under optimum current. I've seen that before in SHG systems. Are you able to open up the head and trace the pins to manually determine pinout? (a nightmare, I know!)

Only thing else I can think of is to shoot an email off to Sam Goldwasser and ask for his input.

probably, but it'd be a challenge i'm sure with all the electronics and the circular port. I'd rather not break the seal either. It'd be nice if I could just change the driver settings. that's all I really need frankly... I wonder if I can coax melles griot into giving up head set up procedure....since this head isn't going to be industrial anymore....not likely.

 

[ultimatekaiser]

anyway... pics! sadly the color doesn't show right. it looks more 532 ish in the pics....its more the color of the LED on the driver/PSU. more on the way