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How much can a diode be overdriven?

Raybo

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I know there are a few factors to be considered, but just to make things equal let's suppose...

You are using a very good heatsink and are using a conservative duty cycle, and let's just say the diode is rated for 25mw by the manufactor.
What kind of mw's could you get without killing the diode in a short time?

Thanks as always,

Ray
 

crocie

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from what i can gather, it really differs from diode to diode.

But, i think, open's can be pushed much further.
 

GooeyGus

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There's really no way that anyone could give you any sort of reasonably accurate answer. Not only will it vary from model to model, but it varies from diode to diode. It may die at 50mW, it may die at 26mW. You're always taking that chance when 'over driving' a diode.
 

pullbangdead

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Every single diode is different, literally. With laser diodes, you're literally talking about a few atoms changing the characteristics of the laser. The active regions in diode lasers are quantum well, literally only a few dozen atoms thick. A few atoms can be the difference between a laser working a not working, and a few atoms can be the different between lasting at 25mW and 50mW.

We're really talking about how a few atoms can change all the workings of the diode, and it's impossible to get all the atoms in the exact same place every time. There's just no way for all the diodes to be the same, so they have to vary quite a bit.

Now, diodes of a given type, say the PHR-803T will follow a trend, and have the same general characteristics. But to even say "this one went to 50% overdriving, so that one will too" can't be done. Some will fail where other don't. And to not even know what kind of diode it is, or what other diodes like it have done, then there's really no way to know. The manufacturer says it will live at 25mW, so like Gooey said, it may die at 25mW, or it may die at 50mW. With multiple diodes and repeated tests, we may be able to guess where one might live at, but without other diodes it's a shot in the dark.
 

Raybo

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Is this any help................SDL-7501 635nm 15mw diodes.

Thanks again,

Ray
 

ElektroFreak

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You may be able to see 20mW CW out of that diode given proper cooling (just a heatsink should be sufficient), but I wouldn't recommend it as there would be almost no visible change in output. Not to mention that it would most definitely shorten the life of the diode, maybe even to just a few hours.

I'd just be happy with the 15mW or buy a higher-power diode. Probably not what you want to hear, but it's just the truth.
 




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