Fiber pumping for 532nm with 888nm interesting read.

[nuphotonix]

https://spie.org/x15068.xml?highlight=x2404

Very interesting read on a fiber pumped 82w greenie. This side axis diffraction threw me for a loop for a second, but Such a cool Idea. Anyone have a 110w 888nm fiber pump? I got the crystal all mounted with a whopper TEC!
Wups typo thats 880nm

[sbk]

Interesting read, thanks for sharing. That's a damn efficient process for such great quality beams!

[dsli_jon]

...aka, 'What a difference 80nm makes'...

Very-cool... I vote this be Sir planters next bench-project...

j

[mixedgas]

Believe me, We ( myself and Eric) knew about that one long ago. 880 diode prices are not cheap yet. Demand is high.

Steve

[planters]

That's right. The problem is not the 880, believe it or not, even if it is as expensive as hell. Rather, it is taming of the fiber output so that it maintains a narrow and co-axial path through such a long crystal...TWICE! The pump optics are a bigger challenge here than the main cavity.

Anyone who wants to try this can do a poor mans version by rotating the polarization of the pump to be @ 90 degrees to the polarization axis of the vanadate. This will give 4x greater absorption depth or temperature de-tunning the 808nm so that the pump is only say 70% absorbed on a single pass.

I am actually a little perplexed by use of 880 to equalize the absorption depth for the two polarizations. I suspect it is to compensate for the fact that at these higher pump powers the only way to get there is to combine multiple single emitters with fiber splicing and they are unable to maintain a polarized output. What I have done is to take advantage of this differential absorption to dial in, literally, the optimal absorption depth.

The decreased quantum defect (1064 -880 vs 1064-808) will reduce the undesirable heating of the crystal and that is with out question a good thing.

[nuphotonix]

Im looking at an engraving machine with an 880nm ( sry typo)200watt diode. the machine is a total loss, but Id donate it to get a greenie that could be shared for outdoor shows. Wow i can already hear the FAA whining about this one!!

[mixedgas]

SO I will not have wasted Eric's magnificent contribution to the 3 watt project, the replacement table for my milling machine gets home this week. The original was damaged in shipping, rendering the Mill useless. I really should not have spent the money just yet, but I sprang for a new, improved, table, as the cost of Asian machine parts is rocketing up. Their standard of living is reaching parity with ours and the cheap mills are getting beaucoup expensive.

Sadly I will not be there to use it for a while. Greetings from the 12th floor of a hotel overlooking Centre Ville, Quebec City, Quebec. Where this simple American guy has decided he's too far from Home. I'm attending the Canada Chemistry Congress for work. I'll be here a week.

I'd like to take a moment to thank God for this wonderful new job, but this trip is over the top, amazingly, excessive.

So anyways, expect to see the 3 watt green project very soon. With a very inexpensive, unique, fiber pump.

Steve

[VDX]

... have someone tried to replace the pumping arc-lamp in an industrial NdYAG-laser (150Watts CW, 40mJ puls) with a fibercoupled 808nm-diode?

I have two of this NdYAG's here - one 120Watt, the other 150Watt ... and a fibercoupled coherent laserdiode with 25Watts@808nm out of a 0.8mm fiber core.

Any chance it's as simple as pointing with the end of the fiber into one end of the laser rod?

Viktor

[planters]

Hey Steve,

What do you think of Q. City? We were thinking of taking a few days to visit there last week and the weather was not too good and so, ended up on the coast of Maine. Anything worth seeing/doing? Good enough for a few days or not even a few hours?

Oh, by the way the second driver finally arrived and it tested good so I installed the second pump. Everything was looking good; each pump individually producing nearly identical 532 power and divergence, but as soon as they were allowed to simultaneously stare into each other...pop one dead diode. I know this is a threat with high powered diodes and reflections form optics and targets, but I had never experienced it myself and so I guess I got a little sloppy. Oh well, it's not like they cost money. Keep you posted.

[planters]

... have someone tried to replace the pumping arc-lamp in an industrial NdYAG-laser (150Watts CW, 40mJ puls) with a fibercoupled 808nm-diode?

I have two of this NdYAG's here - one 120Watt, the other 150Watt ... and a fibercoupled coherent laserdiode with 25Watts@808nm out of a 0.8mm fiber core.

Any chance it's as simple as pointing with the end of the fiber into one end of the laser rod?

Yes they have, but the problem is that a YAG set up to be driven by a lamp needs homogenous and rod filling illumination. The rod supports a laser mode that largely fills the diameter of the rod and if the rod is pumped unevenly it will produce thermal lensing that will interfere with lasing and if pumped hard enough will fracture.