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FrozenGate by Avery

Now its dead :( 800mw Lasever module

freak diode means a few things around here, usually it refers to a diode that outputs much more power than other identical diodes and/or has a more severe wavelength shift (not applicable here i don't think).
 





you should go with the same diode as before, the beam profile of the diode is ultimately what will determine what it can do. if you buy a more powerful diode, the divergence or profile will almost certainly be different, (not to mention that the same diode could have minor changes as well) and if you can't find a way to use it all then you'll suffer from excess heat as well as loss in power. depends on how the module is set up though.
 
Ah, ok. Do you think it is possible to get a stronger diode for that setup in the module? Where can i get high quality C-mount diodes?
 
if it has similar characteristics, I'd say its possible, but no promises as I havn't seen the guts. Either way will likely take a bit of tinkering with the alignment likely in order to get the most out of the diode.

the general idea is to get as much of the 808nm emission into the lasing medium as possible, focused down far enough to achieve threshold, but not so far that you burn up the crystal and its coatings. (grey track damage) and then pass that beam off as straight as possible through the rest of the cavity using as much of the second crystal as possible, without grazing its sides. (causes loss) and then out the front of the cavity.

problem with different diodes is that the emission properties vary even among 2 of the same diode. no two are the same. some may produce a certain beam at a slightly different temperature or current, and you need as close to 808 as possible, heat will cause it to stray a bit, which will reduce your output. when moving crystals and such, fractions of a mm count. you need a steady hand, special IR protection, and a LOT of patience.

I made a 473 for my friend a while back, and let me tell you KTP is nice. LBO is MUCH more picky, both about temperature and its orientation.
 
ultimatekaiser said:
you should go with the same diode as before, the beam profile of the diode is ultimately what will determine what it can do. if you buy a more powerful diode, the divergence or profile will almost certainly be different, (not to mention that the same diode could have minor changes as well) and if you can't find a way to use it all then you'll suffer from excess heat as well as loss in power. depends on how the module is set up though.
Click to expand...

Didn´t read your post before. But i think i understand what you say. How is it with high power dpss modules then (lets say >10W)? They have bigger cristals and active cooling, but also a bigger beam diameter. What i prefer is a high density beam with good divergence (as the Lasever module was before, 1,5W and <1mrad).
 
Generally the larger beams are just a result of the larger mediums, an attempt at using as much of the crystals as possible, every photon you manage to use is less waste, and less heat in the cavity, meaning a more stable laser. but all crystals are different, and this in part is what dictates what you can do with them. not all KTP will have the same efficiency at a particular size. I personally find LBO gives better results than a KTP a lot of the time for me, even in greens, but it has a lower damage threshold, and a lower nonlinear coefficient, so it has to be longer to achieve the same results a KTP will for example, longer crystal means more $ and more difficult to use, and sometimes more overall losses. it's really a game of averages frankly, sometimes with a little guessing involved.
 
ultimatekaiser said:
if it has similar characteristics, I'd say its possible, but no promises as I havn't seen the guts. Either way will likely take a bit of tinkering with the alignment likely in order to get the most out of the diode.

the general idea is to get as much of the 808nm emission into the lasing medium as possible, focused down far enough to achieve threshold, but not so far that you burn up the crystal and its coatings. (grey track damage) and then pass that beam off as straight as possible through the rest of the cavity using as much of the second crystal as possible, without grazing its sides. (causes loss) and then out the front of the cavity.

problem with different diodes is that the emission properties vary even among 2 of the same diode. no two are the same. some may produce a certain beam at a slightly different temperature or current, and you need as close to 808 as possible, heat will cause it to stray a bit, which will reduce your output. when moving crystals and such, fractions of a mm count. you need a steady hand, special IR protection, and a LOT of patience.

I made a 473 for my friend a while back, and let me tell you KTP is nice. LBO is MUCH more picky, both about temperature and its orientation.
Click to expand...

Thanks for explaining! Helps me a lot to understand what´s important when looking for a replacement diode ;)
 
Indeed you're right :)

which is why I said 100 bucks isn't too unreasonable. non FAC 808 C-mounts are like 30 bucks. but FAC 808 diodes are usually closer to 80-100 last I checked. though you have an advantage, as the CNI modules are easy to adjust. I could likely do yours in a heartbeat, the mobile ones are usually just mounted and not really able to be 'played with' after assembly.
 
Good to have experts around who are willing to help out a noob like me :)
Okay... then i´ll just go for the original diode. I think that is the most effective way for me ;)
I hope to achieve close results as before, because the 1,5W in a handheld was niiiiice :D
 
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numquamretro said:
Good to have experts around who are willing to help out a noob like me :)
Okay... then i´ll just go for the original diode. I think that is the most efective way for me ;)
I hope to achieve close results as before, because the 1,5W in a handheld was niiiiice :D
Click to expand...

Be sure that you get a new driver from him too if you think the old was faulty :beer:
 
Today i decided to disassemble the module. The pic´s show the single parts. I assume the very last ist the diode.
@ultimatekaiser: could you give me some advise what would be the next step and what i have to watch out for? Can i just unscrew the diode and put the new one in?

Opened up the module:



Without the top part:



Top part (crystal?):





Hmmmm...?



And this should be the diode i suppose:



Not sure if i should order a new one :/ would suck if i can´t fix it and waste another 100 bucks.
 
Looks fairly well designed. I can see a lot of thought went into it. Hope you didn't forget the orientation they were in before disassembly. :)

I can see how it was made though. And this is some pretty good stuff
 
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Okay, sounds good. But i need some help with the further steps please :beer:
Oriantation shouldn´t be a problem cause i can tell by the glue remains.
So the next step would be to unscrew the diode and desolder the single connection? Maybe mark the orientation of it before? Is that a typical diode used in other systems too?

Hope i can do that :undecided:
 
Yes. Get a thin pointy sharpie and draw a line in the groove between the diode mount and the base, as close as possible, or scratch it with an blade gently, something that you can notice to line it up again, & replace the diode as exact as possible to the way the other was.

Careful with the top, since the diode is exposed on these. You don't wanna touch/bump it or you'll ruin it. The single connection is the cathode. The base is the anode. Be careful not to make a bridge as you solder.
 
Alright, thank you alot! I´ll give it a try, diode is ordered ;):beer:
 
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