Help request for replacing a laser diode assembly

[MTWallet]

Re: Help request for replacing a laser diode assem

5mW of green output usually requires a 200-250mW pump diode. This is due to the fact that the process of generating the green output is 20-30% efficient at best.

OK, thanks. A 9mm open-can 808nm diode in the 200-250mW range it is. Is there a recommended source that a lot of the folks on here frequent for such bits and pieces?

And if I can trouble you just a bit more, going back to the question about the driver still being good. Would it seem reasonable that it would be built into the mainboard of the main unit which I am seeing 3V output on. (It is labeled laser and there is an A on one pin and a K on the other.) Am I correct in my understanding that the driver is just a stabilized power supply (voltage & current)?

 

[rog8811]

Re: Help request for replacing a laser diode assem

It is labeled laser and there is an A on one pin and a K on the other.)

Anode and cathode for the LD, so yes it looks like that is the output from the driver.
What is the total battery voltage for the unit?

Regards rog8811

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

I could not find any diodes that directly match yours with a quick search, so you may have to hunt a bit to find one.

One helpful tool (although it's a bit expensive) is this laser diode "can opener":

http://thorlabs.com/newgrouppage9.cfm?objectgroup_id=302

With this, you could buy a closed-can diode (probably easier to find) and then cut the can off making it an open-can diode.

 

[MTWallet]

Re: Help request for replacing a laser diode assem

It is labeled laser and there is an A on one pin and a K on the other.)

Anode and cathode for the LD, so yes it looks like that is the output from the driver.
What is the total battery voltage for the unit?

Regards rog8811

Its not battery driven. It is like the attached photo. But the whole unit is driven by 5V-2A.

 

[MTWallet]

Re: Help request for replacing a laser diode assem

One helpful tool (although it's a bit expensive) is this laser diode "can opener":

Good heavens! $129 I guess I ought to ask the question, how much are we roughly talking for a new diode?

 

[rog8811]

Re: Help request for replacing a laser diode assem

Ok so it looks like it is constant voltage, I would guess it is also constant current as that tends to be more important to LD's.

Regards rog8811

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

You should be able to find a suitable diode for between $30 US and $50. Perhaps less, even. 808nm diodes don't tend to be too expensive until you get into really high powers (5W-60W). GooeyGus here on the forum has a can-opener, and he is willing to open up diodes for people, all you'd have to do is send him the diode, and he'll cut off the can. GooeyGus is a trusted member of the forum, and can be trusted to do excellent work. Here's a link to a thread describing his services: http://www.laserpointerforums.com/forums/YaBB.pl?num=1210699419/20

Hope this helps!

(Ordinarily you would have to send the unit off to have it repaired, which is expensive, so doing it yourself will save you money even if you had to buy can-opener to do it..)

 

[MTWallet]

Re: Help request for replacing a laser diode assem

What is the general consensus on aixiz lasers? I did a search on that name and saw a few posts about using casings etc but nothing as to the quality of the lasers themselves. I'm considering just going with a complete unit from them in the 20mW range instead of repairing, would that be a mistake? Are they chinese junk, or do they have really short duty cycles?

By the way, thanks for the tip on sending a LD off to GooeyGus to have the can removed, I might have to do that.

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

I bought three 50mW "tunable" green lab modules from Aixiz for $65.00 each. They all produce over 100mW of output, and one of them has been powered up for 2 months continuously (to test the lifetime) and has had no problems. So far none of my modules has given me any significant problems.. They are cheap chinese modules, and other peoples reviews have occasionally been negative, so they are a bit inconsistent. I was somewhat skeptical of these units given the price but they have proven, at least for me, to be quite a bargain.

EDIT I should add that the inconsistency is made up for somewhat by Aixiz being very willing to take care of their customers. They'll exchange defective units no questions asked..

 

[MTWallet]

Re: Help request for replacing a laser diode assem

I bought three 50mW "tunable" green lab modules from Aixiz for $65.00 each. They all produce over 100mW of output, and one of them has been powered up for 2 months continuously (to test the lifetime) and has had no problems. So far none of my modules has given me any significant problems.. They are cheap chinese modules, and other peoples reviews have occasionally been negative, so they are a bit inconsistent. I was somewhat skeptical of these units given the price but they have proven, at least for me, to be quite a bargain.

EDIT I should add that the inconsistency is made up for somewhat by Aixiz being very willing to take care of their customers. They'll exchange defective units no questions asked..

WOW, sounds like you can't beat that with a stick. If you happen to have one of those nearby, when you get a chance, could you let me know what the dimensions of the laser head are? Does it have a integrated drive board, or is that separate? Thanks!

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

The dimensions are 85×33.5×33.5mm. Here's a link to Aixiz ebay page for the modules, to give you an idea of what they look like. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=120355567682 They do have a driver included, but you might be able to hook just the laser head up to the wires that used to connect to your other module, provided the circuitry can handle the extra current required by a higher powered laser.

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

Just wanted to add that Roithner Lasertechnik sells diodes that will work in your broken module. Here's a link to their price list:

http://www.roithner-laser.at/All_Datasheets/Pricelists/roithner-pricelist-c-081205.pdf

 

[MTWallet]

Re: Help request for replacing a laser diode assem

Thanks for your previous two replys, looks like the aixiz module might be the way to go.  That size would fit perfectly into the space on the mobolazer where the old laser went, and then I could tune it to whatever power I needed, based on the space I'm using it in.  Now as an aside, if I wanted to use this http://stonetek.org/shop/index.php?...id=220&zenid=21f2360f9c84837ded18f63950880a65 with an adapter ring like this http://www.mi-lasers.com/cgi-bin/sh...hstart=0&template=Templates/SearchResult.html, would that work as something just to futz with on my existing laser body?

 

[ElektroFreak]

Re: Help request for replacing a laser diode assem

That would work perfectly, but you may still need to de-can the diode. Often with DPSS lasers the diode is open-can to allow it to be closer to the crystal, thereby making the crystal absorb more pump energy. Try it closed-can first. If it doesn't work, send it off to gooeygus.

 

[MTWallet]

Re: Help request for replacing a laser diode assem

That would work perfectly, but you may still need to de-can the diode.

Thanks for the reassurance. I'll probably get a couple of diodes at that price, and if it doesn't work in the can, I may try to load it in my small metal lathe and take off the can with the cutoff tool, and if that plan self destructs, I'll send the other one off to be "opened".

 

[MTWallet]

Re: Help request for replacing a laser diode assem

That would work perfectly...

Got the LD and adapter in today.  The LD has three pins on it, is there a standard for which is positive/negative connection? Thanks again to all for the provided help!