Blu ray laser diode roundup

[drlava]

With all of the new, exciting 405nm laser diodes available, I thought it would be helpful to post a comparison chart of the I-P plots of these diodes. Note: the PS3 kes-400a diode wasn't pushed very hard, but it is known that they can't take too much more than is graphed for a long time. The ggw-h20l diode likewise wasn't pushed very hard because of its expense, but its straight output curve continues past 130mW. These tests were all done on the same setup with an aixiz collimator, aperture opened plastic lens.

As more diodes become available, I hope to add to the list.

 

[phenol]

Looks like a rather potent diode! given the anomalies around 90-100mA, I think that currents up to 70-80mA would be safe. The lower Ith implies shorter resonator
Do you perchance have IU curve of the PHR-803 LD?

 

[jayrob]

Your graphs tell the story! Great stuff man!
Thanks for your work...
Jay

 

[pseudolobster]

What's the deal with the 6x? Is that an ellipses mspaint'ed onto the end of the line or does it really cut off at those currents?

I don't suppose anyone knows where they hit their plateau or when they die, do we?

 

[phenol]

someone said he had pushed his briefly to 160 mA(Hemlock Mike?...). Unlike reds, these may die while still in the linear region. They are way too expensive for most people to venture on catastrophic overdriving.

 

[GooeyGus]

someone said he had pushed his briefly to 160 mA(Hemlock Mike?...). Unlike reds, these may die while still in the linear region. They are way too expensive for most people to venture on catastrophic overdriving.

I'll be the guinea pig. I've had mine at around 180mA

Also, I fed my 'weak' xbox hddvd diode close to 140mA for about 5 mins in an aixiz module. Its still alive.

I know many people dont want to risk breaking things, but I feel like we cant truly know what is safe and what isn't until we find the breaking point. As long as we have fun getting there, thats all I care about

 

[flogged]

[quote author=phenol link=1210649211/0#4 date=1210759673]someone said he had pushed his briefly to 160 mA(Hemlock Mike?...). Unlike reds, these may die while still in the linear region. They are way too expensive for most people to venture on catastrophic overdriving.

I'll be the guinea pig. I've had mine at around 180mA

Also, I fed my 'weak' xbox hddvd diode close to 140mA for about 5 mins in an aixiz module. Its still alive.

I know many people dont want to risk breaking things, but I feel like we cant truly know what is safe and what isn't until we find the breaking point. As long as we have fun getting there, thats all I care about [/quote]

The question is what the actual power output was at 140mA - did it seem significantly brighter? My guess is the slope on these is very flat beyond 40-50mA, so you may have been producing a lot of heat with little xtra light.

Would be nice to see a power curve for the 'low' powered diodes from the xbox.

 

[drlava]

What's the deal with the 6x? Is that an ellipses mspaint'ed onto the end of the line or does it really cut off at those currents?

I don't suppose anyone knows where they hit their plateau or when they die, do we?

Hi yes that's exactly what it is, and it represents that the line just keeps going. Where it hits a slope decrease right now is anybody's guess because no one is currently willing to risk a $300 diode just to post a curve

 

[GooeyGus]

[quote author=pseudolobster link=1210649211/0#3 date=1210758491]What's the deal with the 6x? Is that an ellipses mspaint'ed onto the end of the line or does it really cut off at those currents?

I don't suppose anyone knows where they hit their plateau or when they die, do we?

Hi yes that's exactly what it is, and it represents that the line just keeps going.  Where it hits a slope decrease right now is anybody's guess because no one is currently willing to risk a $300 diode just to post a curve [/quote]


Well I can tell you with 100% certainty they die after a few seconds at 270mA :-[


Also, the biggest question here, is that I'm about to hit the order button on another 6x drive. BUT do I buy the 6x drive again or should I go with the x-box sled? they seem pretty on par with each other so far! But I want high power with good longevity, so I'm guessing the 6x is where its at.

 

[IgorT]

Wait.. Up untill now (till Jayrob corrected me), i thought your measurement was done without optics.

I thought they put out 80mW at 90mA before the lens.. At least that's what part of your other thread would seem to suggest, with all the Climbaks measurements and so on. Also, the first one i measured was 80mW without optics and 70mW with an opened clear AixiZ acrylic lens.


Are they inconsistent or was the diode you measured a really hot one?

 

[dar303]

Good info!
I have read a lot of threads about the xbox-diodes but never seen any data about the forward voltage of these diodes, anybody know that?

 

[IgorT]

Good info!
I have read a lot of threads about the xbox-diodes but never seen any data about the forward voltage of these diodes, anybody know that?

I already mentioned it in two other threads actually.

At 89.5mA, the voltage across my diode is 5.14V, and the regulator slowly lowers this to 5.11V, as it warms up, to keep the current constant.
At 96.5mA, the voltage across my diode is 5.35V, slowly dropping to 5.31V, as it warms up. Probably lower later without good heatsinking.

Others may be different. They vary in the power they put out at a certain current as well.

 

[dar303]

Thanks!
So there is no absolute forward voltage? I'll have to measure a bit and present the results here when my units arrive.

 

[IgorT]

The forward voltage of any diode (not just laser diode) changes with the current through it.

There are also certain differences between each individual diode. There is a certain Vf range for a certain current usually shown in the datasheets.

 

[phenol]

Vf also changes with temperature and with those BRLDs the change seems fairly prominent - at about 27C and 110mA my 6x has ~4.5V on it. I chilled it in the fridge for a little while down to 8-10C and Vf jumped to >4.8V