The Big Green Thread (I'm gonna regret posting this in the morning)

[mixedgas]

2 pieces at 11 watts for initial trial. Each supports a 200 micron fiber.

Fedex made a unfortunate procedural error with the diodes. I had to analyse their problem and suggest a solution to them.

We'll see if they can execute it.

Core of the story, some one used Ground, and shipped it "Hold for Pickup" as I requested.
Hold for pickup is not a option on Ground, so the local Fedex office rejected the package and sent it back.
I caught it before they had them back on a airplane tonight.

I was within 50 feet of the diodes on Saturday and they told me they had not arrived nor were they in the system. Yet the tracking said they were in Akron and ready for pickup. I am not amused.

All they had to do is call.

I went back today and had a few words with the office manager.

Steve

[macona]

That's odd, I have had several items held for pickup with FedEx ground.

[mixedgas]

I suspect twittery of some form.

Steve

[Meatball]

^^What happens when twitter.com is over-used.

[VDX]

Hi folks,

... someone interested (or has an application for) fibercoupled pump-diodes with 975nm wavelength and 5Watts or 9Watts? - have some ten of them salvaged from broken fiber lasers.

I'm using them (and another with 25Watts@9Amps) sometimes for laser-sintering with powders or -cutting dark plastic sheets ...

Viktor

[mixedgas]

And Now for Something Completely Different:

If you own a FAP with a fat bundle and build the laser described in this attached paper, you will probably have loads of green on your wattmeter. It probably will not modulate well at all and will most likely have a huge beam divergence.

Clues: Little to no mention of output beam specs. Hint at astigmatism issues in text, as a warning to the subtle reader. However, they set the published world record for Green conversion rate for a few weeks to months. Lots of talk of thermal lensing.

It does give us a hint of the effects of thermal lensing, and that is what is important.

This paper probably got them more funding, and that is always important. It lead to their group developing better lasers.

This is a 1999 paper, so pump diodes have came a long way.

If you have the parts, you can try this design. But I would NOT endorse ordering ANY parts to build it from scratch. There are better designs in the pipeline. This is here for learning.


See attached file DPSS-PL-1-1 and DPSS-PL-1-2

JUN-HAI et al, Chinese Physics Letters VOL 16 #7 1999 is attached for Educational Use for a short period of time.

PULLED ATTACHEMENT PER EDU USE FAIRNESS>>>


Steve

[mixedgas]

I'm attaching another paper for educational use.

This is not the final design either. There is something else better in the pipeline. It does give the discerning PL reader a LOT to think about.

This is one that I would consider building if I already owned a older, working, FAP. Its not bad, but its not state of the art.

The beam quality is, however, not bad at all. In fact its better then most currently made low cost lasers. Because many of them are side pumped. Side pumping is horrendous at 1-2 watts of green. However it is cheap to build. That is why we put up with commercial lasers with shifting modes and horrid modulation.

We'll discuss this at a later date, I need to get to work.

Liu, et al, Optics Communications Volume 173, 2000, is attached for educational use for a short period of time.

PULLED ATTACHEMENT PER EDU USE FAIRNESS>>>

Steve

[mixedgas]

There are people on PL last year who were looking for those diodes for home made red fiber lasers. Perhaps you should post that in BUY,SELL, TRADE.

Were any of those fiber lasers modelocked?

I'm not so sure that is a ND:YVO4 pump band. I'll check, but I doubt it.

Steve

[buffo]

1.8 volts, 13 amps. So Size it for 15 or 20 amps.

Copy that. Interesting that the forward voltage drop is so low. But no biggie. 15-20 amps it is.

Nice to see ya here Adam .. gettin' all mixed on up in here in the big green green thing ..

Hey Steve-O... Long time no see, dude! Yeah, I've been keeping a lower profile these days. Long days at work, and longer days at home. But I did jump into this thread a while back with the idea of providing a decent driver (and possibly a TEC driver too) for the pump diode.

The PL-Spec projector project I've been working on will also need a driver, so since the driver design we have is scalable from .5 amps to 50 amps, I figured it was the perfect candidate for both projects. (Plus this allows Eric, Steve, and everyone else to focus on the hard part - namely the cavity details - without having to worry about a driver too.)

Slow going though. Between the holidays, work pressures, and other issues around the house, it seems I don't have time to do anything anymore. But it will get done, one way or another.

Adam

[badger1666]

As much as i would love to have ago at this one , where on earth do you find the mirror ?
Custom coated ? Or does somewhere hold stock of this sort of mirror

I'm attaching another paper for educational use.

This is not the final design either. There is something else better in the pipeline. It does give the discerning PL reader a LOT to think about.

This is one that I would consider building if I already owned a older, working, FAP. Its not bad, but its not state of the art.

The beam quality is, however, not bad at all. In fact its better then most currently made low cost lasers. Because many of them are side pumped. Side pumping is horrendous at 1-2 watts of green. However it is cheap to build. That is why we put up with commercial lasers with shifting modes and horrid modulation.

We'll discuss this at a later date, I need to get to work.

Liu, et al, Optics Communications Volume 173, 2000, is attached for educational use for a short period of time.

Steve