New Nichia 9mm 1W 520nm diode (NDG7475T)

[bloompyle]

I have a monochrometer, yes. The change will likely be between 3-4nm, depending on how hard you are running it above spec. ARG tested this diode for current vs wavelength, as well as power. See here.

When run low, 520nm diodes tend to be between 515-517. High, 522-525. Is it really that high? No. Am I picky about getting the closer to 500nm as possible? Yes.

 

[KRNAZNBOY]

Running these diodes really cold will get them to blue-shift a bit right? If you TEC cool it to sub-0c temps, then you would run it high and still have sub 520nm right?

This is not for a portable build however

:beer:

-Matt

 

[bloompyle]

In the past, chilling didn't do too much really. However, that being said, you could likely keep it around ~518-520 with a TEC.

None of this is quotable, just speculation based on other 520nm diodes. We never cold tested this diode.

 

[lazeristasUVISIR]

When run low, 520nm diodes tend to be between 515-517. High, 522-525. Is it really that high?

While I can not discuss about highness, but eyes notice color difference [5-10 nm]. However, my experience is with various diodes at the same low power.

 

[The Lightning Stalker]

Planters did cryo testing on the red and blue diodes and they were completely different. He should do the
same with the greens. I would expect them to be similar to the blue since they have a similar chemistry,
but maybe there will be some surprise. You never know until you try it.

 

[bloompyle]

Exactly what Stalker said.

He did cryo tests on a 445, a 638, and a 658.

The 445 dropped a couple nm before it stopped working. The 658 dropped to maybe around 650. The 638 went all the way down to -191C doing fine, at 608nm. He took two of the P73's, combined and cooled them. 2W @ 608nm.

The smaller 520nm diodes have also been cooled. Resulting in 1-2nm difference (changed from current to current) relative to the same current at room temp. These tests were either done at 0C, or -20C. Not sure, but TECed nonetheless.

As far as the 10nm being a big difference. It all depends. 650 vs 660 is not going to be nearly as different as 510 vs 520, or 594 vs 604. It all depends on where you are in the spectrum. Some colors have a wider swath of the spectrum. I.E. the orange spectrum vs the green.

However, in this case, there is a huge difference between even 514 and 523. I have seen this difference with my own eyes. I've seen 514.5 argon, I've built a ~514nm pen, and I've built a few between 518 - 523. These are noticeable differences, especially to a trained eye.

It's just a matter of what you want. Visibility, and just the most green possible? Or the lowest wavelength possible? You can't have both, is what I'm driving at here. Even a TEC won't get you 516-518nm when driving the thing at 2-2.5A. That is, unless this diode is different from all the others. We'll have to wait and see.

 

[rhd]

Quick note - there's a discount on Aliexpress right now - $653 for the diode:
Online Shop NEW 520nm 1W 450nm 1000mW green laser diode Nichia TO-5 9mm package high power LD|Aliexpress Mobile

 

[djQUAN]

It's going down!!!! I'll wait for it to drop to around $200

 

[bloompyle]

Quick note - there's a discount on Aliexpress right now - $653 for the diode:
Online Shop NEW 520nm 1W 450nm 1000mW green laser diode Nichia TO-5 9mm package high power LD|Aliexpress Mobile

Couple things:

1 - "NEW 520nm 1W 450nm 1000mW green laser diode Nichia TO-5 9mm package high power LD"

That's not weird to anyone else?

2 - Still says $769 + $54.74 shipping. Or $730.55 for 10pc bulk.

Perhaps you posted the wrong link?

 

[Shakenawake]

:crackup:

cool, the first dual wavelength diode.

NEW 520nm 1W 450nm 1000mW green

 

[rhd]

The 450 was weird, but clearly just a keyword grab. They describe it as green, and post the right datasheet excerpt.

Re the price, you were just too slow ;p Aliexpresss's sale ended a few hours ago, prices are back up now.

(I bought a 15x XML light for $63 shipped)