Did anyone use the 538nm 5watt Diode?

[SoulFeast]

I haven't seen anything for the divergence on these. Though I have heard it was very low compared to the Mits, beyond that, nothing has been posted on the major threads on these diodes. Might be in a satellite thread, but I haven't dug that far.

Not sure if overshoot is the issue here. I just know that a surge of current to these, that high, can be risky. They're being powered around 4-5A. I haven't seen a datasheet (not posted) but given that we normally overdrive them, I'd assess that the 4-5A is far too high, and all that power at once is troublesome to these diodes.

For more info, here is the main thread posted about these, from the forum's current source.

[planters]

Though I have heard it was very low compared to the Mits

I thought that the divergence on these was actually kind of high for a comparable exit diameter.

[SoulFeast]

With optics added, divergence is great. Of course if you don't add a focal lens, you get crap. With the 50mm FLL's you can get a pretty good divergence.

[planters]

Yes, with optics added the divergence can be as good as you want, but it will be at the expense of a proportional increase in the exit beam diameter. As a comparison, I'm thinking of the beam that exits a Mitsu diode. It is 4mm x 2mm with a divergence in the neighborhood of 1mrad.

[SoulFeast]

Well if you just go off the FAC, it's awful. Exit beam didn't look too large with the FLL. Nothing projector worthy though, but that's not really my end game.

[logsquared]

So I bought one of these to test. The tests at lpf with 5mm diam and ~2.5mRad looked promising. I was unable to replicate those measurements with my sample at higher currents.

At ~4amps with a 50mm fl lens the beam size at the lens is ~10-12mm with a divergence of around 2.6mRad. Threshold was .72A.

The raw divergence of the Slow axis goes from about 4.8deg full angle at 1amp to 13.4 deg at 4.7amps.

The raw fast axis (collimated with FAC) is ~.58 deg

They seem to do the claimed power. My sample was linear to ~4W at 4.7 Amps (the max I tested)

They are very bright. With a 100mm lens the beam calculates to about 1mRad. Even though the beam at aperture is huge with the 100mm lens (around an inch) the beam is really bright. Also the spot can be made to be almost a perfect square.

One thing I did not try was masking the output with a large pinhole (say 5mm) to find out how much power would be lost due to clipping at higher currents.

I think 6-8 of these could be knife edged together for aprox a 10-12mm square beam with 2.6 mRad. Yeah, fat beam but we are talking about 25-30Watts. Laserscope RG anyone?

I don't really have any use for the diode in my projectors. I would sell it for $300 If anyone has a good use for it.

[absolom7691]

I think 6-8 of these could be knife edged together for aprox a 10-12mm square beam with 2.6 mRad. Yeah, fat beam but we are talking about 25-30Watts. Laserscope RG anyone?

With an array of 9mm 445s on top of that, you are looking at 90~100W of white.... damn.

[icecruncher]

[QUOTE=SoulFeast;266846]FYI. These are FACed, but they need to be paired with a decent focal length lens. We've been using a 50mm FLL from ThorLabs. This one here. It works fairly well with these.

Also keep in mind the fact that they need 3A+. It is highly recommended that you give them a soft start. 3-4A+ to these diodes all at once is enough to kill it, or at least do some damage.

Also, these are multimode, not single mode. You're still getting a square with a decent lens. Though it's much better than the bar from a Mit. Still though, not a circle.


Or you could try this lens - they are using this also.

http://www.surplusshed.com/pages/item/pa1041.html

[logsquared]

Its the high divergence of the SA that makes this diode unusable for my application. SA is over 13deg at operational current. Compare that to a P73 which is around 7-8 deg.

Its is still very tempting to bang 6 of these together and throw it at some large 10-12mm scanners. The price would be kinda high compared to using the 8-12 P73's needed for the same brightness. And the P73 rig could have almost 4 time less divergence with the same aperture size.

[-bart-]

I would sell it for $300 If anyone has a good use for it.

It would make one hell of a 3rd brake light as tailgater-repellant !