NUBM44 blue- New Video

[catalanjo]

Hi J
From my notes on the day : DTR package arrives 09:05 14/07/2015
USPS web> Salida Frankfurt, GERMANY ???? still there 13:14 14/07/2015
Cheers

[planters]

OK, some more testing. I'm now at 120 min. continuous @ 4.5A. Starting power was 6.55W and temperature for the bulk host was 20.5C. Now, power is @ 6.34W with the mount @ 40.5C. The mount is only tightly clamped to an optical table without any thermal interface material. The surface of the mount is uniformly warm and so the temperature rise is probably almost entirely do the the interface with the table. This small drop in power does not warrant a more aggressive cooling method, but if the diode count rises or the diodes are mounted in close proximity, then some additional cooling would probably be a good idea. This might just be some thermal grease and a few fans etc.

Both the G-9 and The G-2 lenses produced the same beam measurements and divergence.

[catalanjo]

.........Both the G-9 and The G-2 lenses produced the same beam measurements and divergence.

This is interesting !
Any chance you can stick one of your sexy "magnetic spatial filters" in the beam path just to see if the power is concentrated in the middle or more round the edges of the beam?

Keep up the good work pls
Cheers

[planters]

I can do that, but the results should be similar or better than the first test. The beam "looks" like a typical 445 diode with a primary stripe and two symmetrical, flanking stripes. This is tighter and more symmetrical than the beam from the first diode appeared.

[logsquared]

Both the G-9 and The G-2 lenses produced the same beam measurements and divergence.

And those measurements are?......

[planters]

Look up at post #46.

[logsquared]

What about befor the tele? I am curious if the emitter is actually 3X the width of the M series.

I wish I had the time right now to build an 6-8 banger. I am thinking that leaving the didoes in the original heatsink would be the way to go. What do you think?

[planters]

Those are the dimensions after the beam expander, but before any telescope. There is actually no telescope in this set up.

I am curious if the emitter is actually 3X the width of the M series.

I think the best way to determine this will be when someone takes one of the de-caned diodes an puts it under a microscope.

I am thinking that leaving the didoes in the original heatsink would be the way to go. What do you think?

This is a good question. If the yield from harvesting is a problem that would influence this decision. The original heat sink may not hold the individual diodes in strict rotational alignment. There is no need for the original application. On the other hand, the machine that picks and places them may achieve this with high precision because of the uniformity of the installation process. Over-driving this heat sink may indeed require water cooling (oh goody). Also, the step back that is required for diode combining in the PBS will require the steering optics to achieve this.

A Laserscope does not achieve 50W. An 8 diode beam of 12mm x 7mm with 50W would be hard to stop... literally.

[logsquared]

I think the best way to determine this will be when someone takes one of the de-caned diodes an puts it under a microscope.

I would just like to see the far field spot compared to the M diode. This way I can say "its gonna take X amount of correction to equal a M diode". It seems that diodes don't always emit from the full area of the die. Or at least its hard to tell from the microscope images.

The original heat sink may not hold the individual diodes in strict rotational alignment. There is no need for the original application. On the other hand, the machine that picks and places them may achieve this with high precision because of the uniformity of the installation process.

Good point. I would bet the jig they use is pretty good. I think I would use three sets of cylinders to try and correct 2 diodes at at a time. Then, knife and cube them.

Water cooling to TEC..... Probably.

Hard to beat 40W of 532nm.

[planters]

Hard to beat 40W of 532nm.

Yes, but...

The beam quality with the diode is much better.
The issues with Q switching hazards are not present
The laser would be modulate-able
It could fit in a brief case.

Good point. I would bet the jig they use is pretty good. I think I would use three sets of cylinders to try and correct 2 diodes at at a time. Then, knife and cube them.

Just a point, this would mean three beams and a PBS or 2+4?