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Thread: Where to buy Diodes!

  1. #1
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    Default Where to buy Diodes!

    Is there a supplier that anyone knows of that sells laser diodes?

    Would it be possable to replace the diode in my faulty 473nm 50mW?

    Jim

  2. #2
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    Jim
    It depends on the power and physical type.
    have you stripped it down?
    if its a C-mount you may get one from junktronix he often has 808nm diodes in C mount for sale on ebay up to 4 watts if I recall.
    In the UK photonic products supply didoes or maybe try Roithner in Austria. Its a few years since i bought any from these but the service was good. Only thing is prices are not cheap from these suppliers but you will get 100% quality & a waranty.
    I have replaced a C-mount in a green laser but this was only I think a 1 W and it was a while ago. I didnt get it from Junktronix, as at the time I hadn't discovered him.
    If you have opened it up get some images on here it would be cool to see what they got in there

    Rob

  3. #3
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    Thanks Rob,
    I will strip it down and have a look to see what type it is.
    The original head that I screwed up was a 50mW, would I be able to replace it with a more powerful diode or are the other components matched to the 50mW?

    Jim

  4. #4
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    The main difference between similar heads (in terms of design) is the power of the ir source - give or take.
    The rest of the cavity will be the same - same vandate xtal same LBO or whatever shg crystal, so if you pump it harder and assuming the cooling system can cope & power supply can provide the drive current then you should get more out.
    I dont have this as fact but im pretty certain they build x number of modules and then classify them by the output so if one does say 60mW they will sell it as a >50mW unit if it does 120mW then they can get more money and sell as a >100mW unit, even though the build is the same. (I susspect similar takes place with Computer CPU's and their clock speeds).
    If you had the time, inclination and bravery you may find you can get more by tweaking the cavity alignment. If you put in a bigger diode it would be advisable to do this anyway. I have done this with greens and improved thier output by 10-15%. Also depending on the design you may HAVE to realign it all as the cavity may need to be stripped to get the diode out
    I doubt with a blue you would get as much as 10% improvement but you never know and hey what have you got to loose

    Rob

  5. #5
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    Default

    I've just been having a look at it and I am now very confused.
    I thought the diode was at the back of the head as marked in this picture :-

    but when I stripped it down there seems to be no optics whatsoever in that part.!!!
    There are 3 pairs of wires going to it though, I thought it was for a) TEC, b)Thermo and c)diode.
    What I thought was the diode seems to be some little copper block with a screw going through it onto a piece of aluminium.

    So where is the diode?

    Jim

  6. #6
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    Default

    That little copper cube could be the C-mount diode.

    TRy taking pics of it to see if someone can help identify it
    Remember the future?, That'd today, as you imagined it yesterday.

  7. #7
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    I'll take some close-ups off all the parts tomorrow and post them.
    There is no apperture at all from what I can see on the block, just a screw right in the centre of it :?

    Jim

  8. #8
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    That copper thinger with the single screw is almost certainly the diode, a C-block. Be careful with it, there is a tiny diode chip with a gold wire as fine as a hair bonded to the top of it, carrying current to it. If you haven't seen these, then there's a chance you could brush into them destroying them before you know what you have done. Look carefully with a good magnifier and some very bright diffuse light source, like sunlight off a wall, to have the best chance of seeing it clearly. It's possible to remount diode chips, Sam's LaserFAQ has some texts on this, but it means fiddling with low temperature indium based solders and cactus needles.

    I think you can probably find intact, new C-block 808 nm pump diodes on eBay if you need one. If you get one more powerful than you need, no problem, if it's cheap. It will last longer, under-driven. As far as I know, there aren't many things to stop one C-block diode replacing another, apart from power and wavelength. Differences in divergence should be too small to matter if the focussing lens is gathering all of the light, and the whole point of the C-block is to get good heatsinking and repeatable positioning between different blocks. Identifying it might be tough, I don't think they usually have part types and numbers like transistors, they're often custom made for a specific product, so you'll need to examine it and get all the info you can about what you actually have.

  9. #9
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    lots of good clear close ups of it from lots of angles will be best but certainly a good shot of that diode area will be good.
    oh and the good news is that it looks like the diode is on a separate block that can be removed without disturbing the cavity - the close ups will confirm.

    Rob

  10. #10
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    It is a c-block diode.
    The actusl diode is mounted on the top of the block, ~I can't see the fine wire but it may be there, I need to get my magnifier out.

    Jim

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