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Osram PLT5-488 Aspire Mod

paul1598419

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Hmmm. Didn't think about this diode being decanned as as possibility for increased power. I have heard the window on these diodes haze up over time. Thus this one being decanned. I assume that the Vf of this diode is similar to the Sharp diodes, so it wouldn't be that much more efficient. I could be wrong about that, though.
 

jnrpop

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Hmmm. Didn't think about this diode being decanned as as possibility for increased power. I have heard the window on these diodes haze up over time. Thus this one being decanned. I assume that the Vf of this diode is similar to the Sharp diodes, so it wouldn't be that much more efficient. I could be wrong about that, though.
Yer, i never really thought about what effect/loss the window on a diode could have. In any case i'd choose to leave the can on any diode, but this was a unique opportunity.
Looking at the data sheet, its written TYP 75mA@6V and MAX 110@8V. So the Vf is possibly even higher than the sharp diodes, and thats got me thinking how this flexdrive, if supplying more than 150mA. is even supplying that higher Vf to produce 130mW :thinking:
 

paul1598419

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Yeah, that doesn't make sense to me either. It would appear these diodes have about the same efficiency.
 
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Glad to see another Osram PLT5-488 based build. Looks like you got yourself a really great cyan portable laser!
Also good to see that this build doesn't have this strange box near the dot and you are free to use G2 lens without losing its full power.
It is really sad that we can't get a nice round dot on these cheap cyan diodes we have now using G2 lens.
 

jnrpop

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Glad to see another Osram PLT5-488 based build. Looks like you got yourself a really great cyan portable laser!
Also good to see that this build doesn't have this strange box near the dot and you are free to use G2 lens without losing its full power.
It is really sad that we can't get a nice round dot on these cheap cyan diodes we have now using G2 lens.
Hi Ivan, appreciate your post and good to see you back :beer:

I'm very happy to finally have a PLT5-488 diode :D Yes its great not having the box artifact on these osram diodes and the color is amazing,

After seeing your 488nm laser build a few years back, i've been on the lookout ever since. Can't believe you also paid ~$1500us for your diode, evans paid the same last year. Expensive laser diode.

Now that Sharp has a cheap diode in the ~488nm range, i don't think there will be many more Osram PLT5-488 diodes purchased. But who knows, if the price comes down now members might want an alternative :)

J
 

ZRaffleticket

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Those plt5-488s are only $300/PC now. Though that's still marginally higher than the sharp diodes. I do like not having the box artifact with my plt5-488, though the higher availability of the sharp diodes just feels a lot safer. Though these sharp diodes were branded as 495s so who knows if it's just this batch or not that turned out this low. I'd like to think they'll stay this way but I fear they won't.

The box artifact goes away with the right lenses. G lenses don't mean too much at these low powers IMO
 
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ZRaffleticket,

It is probably even better to use something like 3E glass lens, -- it will eliminate the box artifact (if it does exist) and at the same time lower the divergence.
 

ZRaffleticket

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Actually all the 3 element lenses I have show the box. Acrylic does a much better job at hiding it, though I can still see it even with that. I need to get a 520 2 element and see if that's any better.
 

paul1598419

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It's strange as all the builds I have done with single element acrylic lenses don't show the rectangular artifact at all that I can see, nor anyone who has come over to look at them. There is a bit of light leaking out around the lens, but it is not much and doesn't detract from the very tight dot I get at 30 feet. The divergence specs of these Sharp diodes is excellent.
 
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All right, it is really strange then. Because my 480nm and 502nm diodes do not show this artifact when using both acrylic and 3E glass lens. But there is a noticeable artifact when using G2 glass lens. Also, I do have 2E lens from DTR and this type also helps.
ZRaffleticket, I ... I don't have any thought why this happens to you and why this doesn't happen to me.
But, I do know for sure that for my lasers acrylic lens do the best job. With 3E and 2E lens there is small kind of triangle near the dot on 502nm laser. However, this is far more better and smaller than a regular rectangular artifact with G2.
At the same time, all 3E / 2E / Acrylic lens do eliminate rectangular artifact on my 480nm laser.
 
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badboybilly

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Awsome there is someone else that can confirm the 2 element AR coated lens works well with these diodes, Thanks for sharing your experience buddy!
 
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i can confirm that i had better results with a 3 element glass lens coated for 520nm on my latest 505nm build(im planning to upload it soon) than acrylic lens,the reflection box is completely invisible. it has some wing reflections but are far from the clean dot to bother me.acrylic didn't had the box reflection either but the wings and splash was abit worst.never tried a 2 element as i don't have one
 

paul1598419

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Not sure what you mean by "wings", Chris, as these are single mode diodes. There is some light leaking around the acrylic lenses, but it isn't enough to bother me. At 30 feet the dot is tiny. 1-2 mm.
 
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Not sure what you mean by "wings", Chris, as these are single mode diodes. There is some light leaking around the acrylic lenses, but it isn't enough to bother me. At 30 feet the dot is tiny. 1-2 mm.
check Bacon's thread,i posted a pic there,i think we are talking for the same thing paul as mine is only visible at very short distances between laser and target.preety clear dot on far beams :D
 

jnrpop

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I think its time a few members create a comparison thread with output photos, and the different lens's :D It feels like everythread on LPF now has 2 pages of conversations about what lens does what, what lens kills the box, but i havn't seen anyone post any proof of anything...... Comparison thread in the "OPTICS" section :bowdown:
 
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