Freak 520 diode?

[logsquared]

I am working on some modules with lots of 1W 520 diodes. When setting up the last diode block I noticed something odd. One of the diodes was noticeably more yellow. Almost 532ish. This diode had a slightly higher threshold current as well. To bad these aren't binned for wavelength.

[flecom]

I know the 462nm diodes can drift way up to 470+nm if you drive them hard enough, maybe it was the higher current??

[logsquared]

Actually, the photos were taken just a few mA above threshold. The color seemed to hold even at high currents.

[planters]

The 520nm diodes are strained lattice GaN junctions. The 445nm diodes are GaN junctions as well. I suspect that like the 462 diodes there are some 520 junctions that shift downward.

I am working on some modules with lots of 1W 520 diodes.

How are these modules working out?

[norty303]

Wonderfully I'm hoping

Wow, cameras are renowned for not showing these things effectively, that's quite a difference!

[Crazy]

That's pretty amazing! I have wondered since these came out why we haven't seen any high/low wavelengths...probably because they aren't and can't be bought in abundance, so we don't get to see the differences that are easily shown when there are hundreds of diodes in use (like the 445's). I would love to see that diode on a spectro.

[logsquared]

How are these modules working out?

good other than remembering how much I love to cut tiny mirrors.

Wow, cameras are renowned for not showing these things effectively, that's quite a difference!

Yeah, it was totally obvious from the minute I put power to it. I would say the photo is pretty close. If anything, the photo makes the 520 look more blueish than in person.

I would love to see that diode on a spectro.

I used a diff grating on it but haven't done the math.

[planters]

I would love to see that diode on a spectro.

You might set a "normal" 520, the "special" 520 and a 532 DPSS through the grating and see if the special chip is closer to one or the other.

[logsquared]

You might set a "normal" 520, the "special" 520 and a 532 DPSS through the grating and see if the special chip is closer to one or the other.

Yup, exactly what I did. By my math I get 521.6nm and 526nm. hard to believe such a huge visual difference for a few nm. The room for error is pretty large in my measurments (used a tape measure).

[logsquared]

Wouldn't it be cool to collect as many different wavelength diodes as possible. Then knife edge/ dicro them into a relatively large fiber (200um?) just for use with diffraction grating effects (and lumia)