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FrozenGate by Avery

505nm and 480nm diode RESULTS

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So I just fired up my 473nm diode I got from Zach.

At threshold it was at around 473nm-474nm. When I did my wavelength measurements I forgot to heatsink the diode module.
But I notice something interesting, at 100mA the spectrum split into two peaks, one at 475nm and another at 477nm, with 477nm being only 8% less intense. At 230mA the wavelengths were 476nm and 478nm, with about the same ratio.

I am very sure that this two wavelength effect is mostly result of temperature, because after I realized that the module was getting too hot I let it cool off and then measured the wavelength quickly at 230mA and the spectrum was a single wavelength at around 475nm. I estimate that the module reached a temperature between 100 F to 130 F. I suspect that a large cause of the diodes wavelength shift is only related to the temperature. I guess that could be tested to see for sure by keeping the diode current the same while changing the ambient temperature.

Luckily the diode seams to have survived just fine.

Have any of you guys that have spectro'd these diode noticed anything like this?
 
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I had mine heat sinked very well before raising the current to levels you did, so, no, I didn't. Mine were in a large copper heat sink and never got near that hot.
 
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That's odd. Maybe these are the product of stolen research on the 476/480's that popped up a while ago. At the very least, I'd imagine they do it for the same reason as one another...

Though on those, the higher line appeared when overdriving them, and would eventually outperform the original line.
 
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Yup! Nothing came close to >480nm, so I opted to buy these instead.

If I don't kill the 502 trying to build it, I'll be selling the 502.7 at cost. That may take a little while as I have no idea what driver to get/use to drive at ~125mA.
 
Are you just driving it so low to try to insure the integrity of that WL? I can't say that it will help as they do warm up over time. There are some 125 mA drivers on eBay. Don't have the link as I wasn't interested, though.
 
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That was my plan. I never really cared to get a lot of power out of it, just WL.

Unless you don't think the WL will shoot up much if I feed it a decent bit more. Do you have figures for wavelength vs mA on one of these?
 
ZRaffleticket said:
That was my plan. I never really cared to get a lot of power out of it, just WL.

Unless you don't think the WL will shoot up much if I feed it a decent bit more. Do you have figures for wavelength vs mA on one of these?
Click to expand...

Once my "505nm" diodes from Newgazer arrive I can got some data on wavelength shift. Although, I don't think my diodes will arrive for another week.

I'm curious what the numbers are for wavelength shift with current in the 473nm/480nm diodes (when properly heatsinked:D). Maybe I'll test that tomorrow if I find time.
 
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ZRaffleticket said:
That was my plan. I never really cared to get a lot of power out of it, just WL.

Unless you don't think the WL will shoot up much if I feed it a decent bit more. Do you have figures for wavelength vs mA on one of these?
Click to expand...

On the ones you had that were higher than the 505nm ones, they only shifted about 1nm from 50 mA to 200 mA. But, that wasn't taking in to account of heating up for several minutes. I had them in a large copper heat sink and only had them on as long as it took to get an accurate measurement. Now, the one that Rich sent me was 502.1nm at 75 mA and went up to 502.9nm at 280 mA. I did try it at 300 mA for a moment to see if it would shift more and it didn't. But, I didn't have it there long so I can't account for heating up.

I do have several coming from Newgazer that Dr.Laser had them ship to me. So, I'll be able to give you some information about them once they get here.
 
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Oh, that's far more WL stable than I thought they'd be. Well. I just might end up pushing them more. Maybe.

I just bought some of the aixiz linear drivers with the pot on them. Rated for up to 10v in and 80-500mA out. I believe that should work... correct me if I'm wrong.
 
Linear drivers put out more heat than other drivers. You'll have to have three Li-ion batteries if you use it in a handheld. I'm still planning on using a boost driver, but could use a buck if I used three batteries. I still have an adjustable X-Drive from Lazeerer. But, a boost is really the only way to go IMO.
 
So I did manage to get get more data on the wavelength of my 473nm diode at different currents. And I got this graph...
11957-473nm-laser-diode-wavelength-vs-current-graph.png


And of course it should be noted that the spectrometer's accuracy is +/- 1nm, I just included the last digit to give a better relative reading.
The lasing threshold was at 47mA.

EDT: I should clarify that this time the diode was heatsinked thoroughly and that the spectrometer used was a Ocean Optics USB2000.
 
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Not too bad. You got close to 477nm with your diode. I hope it holds up for you at that current. I will be pushing mine to 350 mA and will heat sink it well while keeping the duty cycles short. Mine should do 477nm, but might go a bit higher with heat.
 
We bought two 480nm diodes and two 505nm(SB147EC91) diodes off LPF but the results are quite disappointing.

The first 480nm diode runs smoothly at 200ma in our guardian housing, we will run it continuously for a week to see how's it holding up.

Yet the second one led'ed the first time we put it into test at 200ma, literally the first second, no flash, super weird.

And there is no stop of that, the first 505nm ran a good ten seconds at 150ma before gone to led mode(in the challenger housing, copper heatsink) and the second one faced the same fate as the second 480nm diode.

Maybe we received a bad batch...but the results are very different from we saw in the thread...

Well, at least we have some pictures of the 100mw 480nm guardian:
480 (1).jpg 480 (2).jpg480 (3).jpg 480 (4).jpg
480 (5).jpg 408 lpm.jpg
 
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Podo said:
We bought two 480nm diodes and two 505nm(SB147EC91) diodes off LPF but the results are quite disappointing.

The first 480nm diode runs smoothly at 200ma in our guardian housing, we will run it continuously for a week to see how's it holding up.

Yet the second one led'ed the first time we put it into test at 200ma, literally the first second, no flash, super weird.

And there is no stop of that, the first 505nm ran a good ten seconds at 150ma before gone to led mode(in the challenger housing, copper heatsink) and the second one faced the same fate as the second 480nm diode.

Maybe we received a bad batch...but the results are very different from we saw in the thread...

Well, at least we have some pictures of the 100mw 480nm guardian:
Click to expand...

Awesome efforts Podo, it looks like if you simply breathe on these diodes they'll LED... That's too bad, I would've liked to see a reliable source for these diodes and even more a pocket series with one of these nicer wavelengths.
 
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