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Alaskan

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I tried using a different lens to focus the output to a point, but unfortunately, its focal length was so long that I could only get the beam to focus to a spot that was perhaps a inch smaller diameter at 12 feet away than the lens made to couple with the FAP, I think the beam diameter was about two inches wide at that distance when trying to focus a 5 inch FL PCX lens with it, instead of about three. I believe if a much shorter focal length lens were used, you might be able to focus it to a smaller point at a distance but you are fighting the huge amount of divergence this laser has, so not sure.

Here's another photo, this one shows how fast the beam diverges without the lens in front, the Kleenex box is about a foot away from the laser output. Never mind the date on the photo, I just received this camera from an ebay sale and didn't update the unit to the correct date prior to taking.



Here is a better photo showing the individual beams combined into the fiber output, at least, the edges of the outer ones:



This photo was taken at low current, just enough to make a bright spot on the wall, but not enough to see the beam with the camera. The photo I posted showing the fiber output against a piece of card board or the Kleenex box did not show this pattern as it should have because each of the combined emitter outputs are regularly spaced and very distinct, although all overlapping some. At higher output I think the camera is being blasted with too much IR light to distinguish well enough.
 
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Alaskan

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IR FAP800 laser mounted on a pedestal pointed at a tree 100 feet away running at far below full output power but the camera was able to pick it up well. As you can see, the divergence is huge at about 18 mRad and becomes a spot light at a distance instead of a thin laser beam. I had a picture up earlier which wasn't as good, replacing it with this one which better shows how the individual beams break-out when spreading into the distance. The Camera I used is a modified Kodak EasyShare M1033 HD 10.0 MP with its internal IR filter removed. The camera seems to get confused on auto-focus when taking pictures of IR, but this one isn't too bad.

 
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Gabe

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Really cool pics Alaskan. I didn't catch it, what's it outputting in that photo and what's its full output power?
 

Alaskan

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Really cool pics Alaskan. I didn't catch it, what's it outputting in that photo and what's its full output power?
That particular FAP can put out up 12 watts if run at full current, it probably was putting out a couple of watts or more at the reduced voltage I was running it at. I have other FAP800's which can put out up to 40 watts I shared some photo's of earlier. Even at a couple of watts out I wouldn't dare point this thing anywhere it could hit someone, as any laser, of course. When using IR for beam shots it is essential you mount it something which can't be tipped on accident, or moved as you can't see, except through a camera as I was using, where it is pointed. This isn't something I'm going to be using again like this, I just wanted to see what the beam output looked like after a hundred feet or so. As I expected, the beam became so wide you could see the individual fiber outputs as separate beams. By the way, you can buy IR spot beams which will do this same thing on ebay for hunting.

Here's one of them that uses a laser diode too, but at 250mw, still too powerful to look into when close to the output, I bet:

http://www.cabelas.com/product/PULS...=GoogleProductAds&WT.z_mc_id1=03922183&rid=20
 
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RedCowboy

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It should show up well, with IR lit cameras the 808 makes a very dim pink and they brag about no glow IR lighting for home security cams by using IR led's in the 900's.
It's the same kind of CCD so I expect it will show up just fine.

That FAP cluster looks good, it's uniform round, with the right optics you may be able to expand and focus to a decent distance.
I wonder if used to pump a crystal what king of beam you would get, of course you would need to get the divergence down first and make it fit your crystal, but I wonder if it could produce tem00 or if it would be impossible?

I still want to go with a single emitter, but I love how round that output comes out, I know it's a bunch of fibers/dots, but the alignment is impressive, I know it is made for long distance communications so it needs to be uniform....it could have possibilities.
 
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Alaskan

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The FAP800 was made for cutting, the fibers are only used to increase the power into a single beam. I have a 15 watt 808nm 400um single emitter laser diode I will be working with later to build a portable battery powered laser out of. I have no idea if a FAP800 can be used with a crystal or not, I think that would be a tricky task to interface plus too much power for any surplus KTP crystals I've seen, after the YV04 crystal, of course.

Here's another photo I took and had taken tonight, this is a 8 inch/200mm diameter PCX lens in a kitchen strainer cone coupled to my Ehgemus 1.5 watt 520nm laser pointer. I have no idea what the exact divergence is with this big lens, but I imagine it is probably less than .1 mRad:





Another beam shot: http://i853.photobucket.com/albums/ab95/LaserProject/big1.jpg

The ghetto black tape was used to get the optics right as a prototype. I had started with another 8 inch diameter lens with a longer 10 inch focal length which didn't work out well, swapped that lens for one with a shorter 8 inch focal length to get the beam focused close to infinity. I'd like to shorten the cone some and insert a zoom focus mechanism later, then have something machined so I don't have this ugly tape.

This strainer is similar to the one I used, except mine is 8.25 inches wide at the top rim: http://www.ebay.com/itm/Vintage-Wea...ner-No-334-1-2-with-wood-pestle-/171973857743 - Of course, I had to cut the tip of the cone off to insert the pointer.
 
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diachi

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The FAP800 was made for cutting, the fibers are only used to increase the power into a single beam. I have a 15 watt 808nm 400um single emitter laser diode I will be working with later to build a portable battery powered laser out of. I have no idea if a FAP800 can be used with a crystal or not, I think that would be a tricky task to interface plus too much power for any surplus KTP crystals I've seen, after the YV04 crystal, of course.

A FAP800 could be used with a crystal, though it'd need to be a fairly beefy set of crystals, not one of those little bonded YVO4/KTP pieces we find in pointers.

See this video if you haven't already: https://www.youtube.com/watch?v=Pp9hliLJjg4

It's fairly involved, but the beam quality/diameter/divergence is absurdly good.

You *might* be able to achieve *some* green with a larger set of bonded crystals if you are careful not to destroy them with all that power. It wouldn't be nearly as efficient as the system in the video.
 

RedCowboy

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@ Alaskan: Looks like you are getting some distance with your 520.
Also I wanted to rep Alaskan for this awesome pic but it won't let me yet. Ill owe you 1.




@ Diachi and Alaskan
Yea mine are FAP800-12W and 25W 19 emitter, Some came in a heavy brass colored box with all the connections brought out to terminals cathode, anode, monitor for temp and the peltier pad connected to a modular plug deal.

Maybe it said in the ad on flebay something about being retired tel-com, I can't remember, I am no doubt mixing these up with some other units.
I have a lot of stuff in boxes that I got a deal on and put away, I'm a bit of a pack rat.

Tech Ingredients sure does a good job explaining things.

Thermal control looks like a PITA for portables when crystal pumping at higher powers, but that beam quality is nice.

I wonder if being multi emitters, albeit nicely bundled, would be a problem for crystal pumping, if the crystal pair was beefy enough and temp control could be maintained.
 
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diachi

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@ Alaskan: Looks like you are getting some distance with your 520.


@ Diachi and Alaskan
Yea mine are FAP800-12W and 25W 19 emitter, Some came in a heavy brass colored box with all the connections brought out to terminals cathode, anode, monitor for temp and the peltier pad connected to a modular plug deal.

Maybe it said in the ad on flebay something about being retired tel-com, I can't remember, I am no doubt mixing these up with some other units.
I have a lot of stuff in boxes that I got a deal on and put away, I'm a bit of a pack rat.

Tech Ingredients sure does a good job explaining things.

Thermal control looks like a PITA for portables when crystal pumping at higher powers, but that beam quality is nice.

I wonder if being multi emitters, albeit nicely bundled, would be a problem for crystal pumping, if the crystal pair was beefy enough and temp control could be maintained.
You'll have no issues pumping with bundled fiber! He may be using bundled fiber in the video - I'm not sure.

My 2W Melles units both use 19 emitter fiber coupled LDs, think they are ~20W diodes. Fibers are bundled just like the FAP diodes, probably 800um too. Just need to focus the output from the fiber with a short FL lens so that you get a nice small beam waist inside of the vanadate. And align it all of course...




Obviously this is all very simplified, you need to pick the correct optics, align it all, control temperatures, not cook anything with all of that power and so on.
 
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RedCowboy

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Thanks for the info, learning and burning up stuff is part of the learning journey, I have probably 100 broken 532 modules and I can see the IR pump diodes focus on my cell phone better than my digital cam, even with just that and safety glasses I have aligned surviving crystal pairs with surviving pump/drivers and a replacement lens and made green beams.

It's more fun for me to make something even if it's not pretty than just buy something, although some things I cant create out of junk and determination.
 

diachi

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Thanks for the info, learning and burning up stuff is part of the learning journey, I have probably 100 broken 532 modules and I can see the IR pump diodes focus on my cell phone better than my digital cam, even with just that and safety glasses I have aligned surviving crystal pairs with surviving pump/drivers and a replacement lens and made green beams.

It's more fun for me to make something even if it's not pretty than just buy something, although some things I cant create out of junk and determination.

I'd like to build that kind of thing, but I don't currently have the best tools for the job, or the money. At the least a drill press would help. I have two ~20W Fiber coupled 808nm pumps sitting there just waiting to go into a Z-Fold... You're right, it's way more interesting to build these things from the ground up and learn something in the process. Even if you do destroy some optics along the way.

Maybe I'll start off with a quad diode build with spatial filtering and all that good stuff and then worry about build a Z-fold when I have the resources.
 
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