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^That's right actually. At low powers only one mode is present. The output is still a line rather than a circle, but the divergence is considerably lower.
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RGV or RGB?
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mfo
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Hmm, I'm honestly torn on what I should do. I really want an RGB now, but I'm a perfectionist. I want to be able to shine a bright white beam farrr away. How far do you think it'll stay white if I keep the 445 low power?
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It'll stay white for a VERY long time regardless of the divergence of the individual lasers so long as the beams are properly aligned. The cross-section of the aligned beam should look like a target, with each beam centered within the other (or as close to that configuration as you can get). If the beams are all properly aligned, then the colored fringes on the edges of the white beam (which are caused by the beams being slightly different diameters and divergence) will only be visible when up VERY close to the beam. The overall effect will be a solid white beam.
Don't stress yourself too hard over alignment. As long as the beams are as close as you can get them, then from the audience perspective the little quirks should go completely unnoticed.
Don't stress yourself too hard over alignment. As long as the beams are as close as you can get them, then from the audience perspective the little quirks should go completely unnoticed.
mfo
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Sounds good. Now, I just need to find someone that has a kit....
Edit: I just realized, does Fire My Laser still post on here? I'd love to get one of his drivers.
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goninanbl00d;845943@[b said:
Thanks! - that's a really good start. I copied the thread to my hard drive
where can I get the info on the stuff you left out
..."There have been developments concerning other SHG media for use, mainly BBO and BiBO. These crystals are used for doubling into the deep-UV range, and will not be covered here."...
Are these the crystal sets that need special equipment and rooms to align?
Is this what's needed to make 457nm blue? (BBO + 808nm IR ?)
Why can't some wavelengths be made on a diode laser, directly?
(532nm, 457nm, etc..) when 445nm is able to be put on a diode directly.
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Thanks! - that's a really good start. I copied the thread to my hard drive
where can I get the info on the stuff you left out
..."There have been developments concerning other SHG media for use, mainly BBO and BiBO. These crystals are used for doubling into the deep-UV range, and will not be covered here."...
Are these the crystal sets that need special equipment and rooms to align?
Is this what's needed to make 457nm blue? (BBO + 808nm IR ?)
Why can't some wavelengths be made on a diode laser, directly?
(532nm, 457nm, etc..) when 445nm is able to be put on a diode directly.
Here's a link to Sam's Laser FAQ, from which most of this information was taken:
Sam's Laser FAQ - Solid State Lasers
as well as the RP-Photonics encyclopedia (which is somewhat more up to date)
RP Photonics Consulting - laser and amplifier design, nonlinear optics, fiber optics, fiber lasers and amplifiers, ultrashort pulses, optoelectronics, consultant, training
As for the crystals that need special atmospheric conditions to align, it's stuff like LBO and BBO. Both are extremely moisture-sensitive, and exposure to moisture will cause them to expand, crack, and crumble into dust.
The reason why some wavelengths can't be made into diodes is because a host medium doesn't exist. The current host medium for blue and violet diodes (InGaN) only readily supports lasing at lower wavelengths, and going higher it is extremely hard to dope correctly to obtain lasing.
That's a very dumbed-down explanation, there's a thread about green laser diodes that explains it better than I can.
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I don't think he's posted in a few days, maybe a week or two, and before that a good while. Many members seem to have vanished due to 445nm, but I do believe he sold out of his drivers and said he wasn't going to be making anymore, so you'd have to ask around and see if anyone had a spare one they'd let go, sorry!
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This is awesome, goninanbl00d, thanks for the links and all the other info. It's much more understandable now... I think I'll stick with the 445nm for now, and simple crystal sets for the above 500nm to play with.
I don't feel like having my crystal expand, crack, and turn to dust!
:thanks:
FireMyLaser voted on my poll one or two days ago, so he's still active.
... check the "poll results", so far, ... he voted for the 5.6mm 300mW 635nm diode.
http://laserpointerforums.com/f58/p...ats-your-dream-laser-diode-if-affordable.html
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I'm wondering ...
if the BBO and LBO crystals need a dry environment or they'll crack and turn to dust when aligning,
is it possible to create a small plexi-glass enclosure, where your hands can fit into gloves built into it, when it's closed,
with a peltzer effect wafer based system to make a small air cooler, de-humidifier type of thing?
This way, the "environment" can be portable... and you can align the crystals anywhere.
no need for a special big room.
also, and sorry if this is a stupid question, I had to ask it, it's hounding me ...
why won't the crystals go bad, on a very humid day, when it's inside the laser device already?
if the BBO and LBO crystals need a dry environment or they'll crack and turn to dust when aligning,
is it possible to create a small plexi-glass enclosure, where your hands can fit into gloves built into it, when it's closed,
with a peltzer effect wafer based system to make a small air cooler, de-humidifier type of thing?
This way, the "environment" can be portable... and you can align the crystals anywhere.
no need for a special big room.
also, and sorry if this is a stupid question, I had to ask it, it's hounding me ...
why won't the crystals go bad, on a very humid day, when it's inside the laser device already?
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You're thinking of a humidity controlled cleanroom then right? It's probably possible, but even the dry air of an air-conditioned box will still have water vapor present and it'll be pretty hard to avoid it in any enclosure large enough for your hands to fit inside.
also, and sorry if this is a stupid question, I had to ask it, it's hounding me ...
why won't the crystals go bad, on a very humid day, when it's inside the laser device already?
When I opened up a DPSS blue labby, in addition to the sealed laser enclosure, those crystals were sealed in an air-tight plastic container. So I guess the answer is: because it's well sealed.
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I'm assuming it's water-proof because it also extracts all the air from these
"air-tight" plastic containers, and not just seals air out?
Hmmm...
short of getting a "seal-o-meal" machine So these full clean rooms also have more than de-humidifiers?
How do they keep the water vapor away from the crystals in a room size
environment, if not inside a special "box" as well?
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It takes more than a few minutes for the crystals to "crack and turn to dust." More like a few months or even years to degrade that far. Desiccant in the head (silica pack for example) is more than enough protection.
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Thank you, Cyparagon, ... I thought so, otherwise nothing could be made with them :beer:
take $10 out of petty cash for that one!
or several cookies from the cookie jar