561nm?

As a former owner of a 561nm - It's green and yellow. Depends on what colors saturate your eyes beforehand. Really, it is its own color - chartreuse.

And yes, typically 561nm is DPSS from Nd:YAG's 1122/1123nm line being doubled. Not terribly efficient, and even less practical for anything outside medical/DNA sequencing.

Old review here (color was corrected to as accurate to real life as I could get) - http://laserpointerforums.com/f40/50mw-561nm-pgl-iii-c-review-83748.html

I agree: "As for the color... well it lies directly between 532nm and 589nm. It's neither yellow nor green. It's both, and I still can't decide a color to call it other than chartreuse. It's dead center between those..."

I've heard the word chartreuse before, but until your post, I wasn't sure what it was. Perhaps it has been so long since I've heard the word I've just forgotten.

Edit: adding your photo



I'd call that a nuclear green color, if there is such a thing. Cyparagon, I need your opinion on this, that's all Hollywood, I think.

Y'know those dim limey green LEDs often used for indicators or sometimes digital clocks? Those are a good approximation of 561nm. You and I would classify it as distinct from green, but the general public does not. It's green.

Alaskan said:

I'd call that a nuclear green color, if there is such a thing. Cyparagon, I need your opinion on this, that's all Hollywood, I think.

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Reporting for duty SIR. 's all bullshit, sergeant.

To my knowledge, the vast majority of visible radiation associated with nuclear activity is blue, not green. Even then, if it is intense enough that you can see blue light, you need to leave immediately (if not sooner), or you'll surely soon die to death from death poisoning.

That green color associated with radiation is actually the color that glass takes on when it's doped with uranium. And Uranium doped glass glows in the dark, too, that's where the green glow myth comes from. It's not the radiation, it's the Uranium itself.



Uranium gets guilt by association more often than it deserves. I had a very brief argument with someone who was all fired up about the veterans coming back sick from exposure to DU. He was mad because nobody believed them at first, since their symptoms weren't typical of radiation sickness. And I had to break it to him: "that's because they don't have radiation poisoning, they have uranium poisoning. The radioactive type of Uranium, 235, occurs naturally as a trace element in raw uranium ore, which is pretty safe in itself. Well, they mine that out of the ground, then they process it to extract all the good 235 from the ore, and the now highly purified non-radioactive byproduct is depleted uranium, that's why they call it that, and it's as non radioactive as uranium can get. The reason they use it for armor piercing bullets is because it weighs 60% more than lead, inertia = mass x momentum, so these hit unbelievably hard. That being said, Uranium is a HEAVY METAL, so it stands to reason that it's poisonous in the exact same way that other heavy metals are, like lead and mercury, those will kill you, too, and they aren't radioactive. Nobody has ever had Uranium poisoning until now, because there is no practical way to get exposed to it in a form fine enough to be absorbed systemically. But it seems that making a bullet out of it, and shooting it at a hard target like a tank will do it."
That completely enlightened the poor guy, who noted that the symptoms the vets had were almost identical to lead or mercury poisoning. Everyone is always so quick to assume that if it has to do with Uranium, it must be radioactive in some way, what rubbish.

Cyparagon said:

or you'll surely soon die to death from death poisoning.

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2011 called, they want their meme back.

ElectricPlasma said:

2011 called, they want their meme back.

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You got me there. "X Called; They Want Their Y Back" is a fresh new format never seen before - you're paving the way to greatness, sir! :beer:

Richie89 said:

Yeah looks like it's gonna have a slight hint. I don't know much about this wavelength. But 6000 bucks for 50mw!!?
I'm actually more interested in the beam Divergence. 0.2Mrad!!!! Man if that thing was a watt it would be killer.

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H2Oxide said:

561nm could also be an OPSL. Same goes for 532nm (though it's pretty uncommon). But in this instance, I think the "Diode/DPSS" label on the controller pretty much confirms that it's DPSS.

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They're mostly all DPSS, though the Coherent sapphire and taipan OPSLs do come in 561 flavor. (it's coherent's patented technology)

Pangolin makes decent lasers...and 6 grand isn't bad at all. My Melles Griot starts at 8500 and goes up from there at 10-15mW! Even CNI's are in that neighborhood for a SLM laser. Non-stabilized, you can get a typical one for about 1.5-2K ish. I just sold a 5mW MG for about a grand ish. I have a 20mW sapphire I might sell, but it would be too expensive for most people here most likely.

As for the color, it's one of those that falls in a grey area that's between colors and is therefore subject of opinion...it's pretty green in my eyes but some people say it's yellow. It's a nice chartreuse color, about that of an unripe banana. It looks more yellow in the dark, or next to something like 532nm.

Venture out on a project and build your own 561 nm, start here:

Second Harmonic 561nm LBO Laser Crystal, YAG : Nd 1122nm Lithium Triborate | eBay

This listing is for Laser Optics LBO Crystal manufactured by Melles Griot / VLOC. Lithium triborate crystal is applied for higher power (Q-switched) laser where traditional KTP crystals can't survive. The crystal has 3.2x3.2x4.7mm dimensions and coated both sides with dual band antireflective coating. The crystal is cut for second harmonic generation at 1122nm, one of YAG:Nd fundamental lines. The crystal was targeted for medical laser design (eye surgery) but can be used for other applications as well.

Principal Plane: XY, Temperature: 293K

1122.0(o) + 1122.0(o) = 561.0(e)
Walkoff [mrad] = 0.00 0.00 4.92
Phase velocities = c/ 1.604 1.604 1.604
Group velocities = c/ 1.625 1.625 1.635
GrpDelDisp(fs^2/mm) = 9.7 9.7 81.2
At theta,phi = 90.0 8.0 deg.
deff = 8.35E-1 pm/V
S_o × L^2 = 2.50E8 Watt
Crystal ang. tol. = 7.11 mrad°cm
Temperature range = 7.30 K°cm
Mix accpt ang = 14.21 14.21 mrad°cm
Mix accpt bw = 104.17 104.17 cm-1°cm

That's not a bad price for it, but I would want something CW. It might be used for such a project, but wasn't manufactured to do so.

OK, here's a KTP you can use at CW: Raicol KTP SHG 1123/561 nm Yellow Laser Crystal 3 x 3 x 5 mm | eBay

Here you are. This picture is pretty accurate for the colour.



Such a lovely wavelength of which I need to someday own.

Just like 589, you will probably see a shift in colour in different light conditions. It will probably look more yellow in the dark, whilst more green in daylight.

Yep, that's Banana green if I ever saw it, or yellow depending upon which side of the fence you are on with your opinion. Kinda of a erie glow to me suitable for a Duke Nukem laser weapon.

To me its still green. I class anything from 575-585nm as yellow. 561nm is lime green, 589 is golden/sodium yellow and 594 is going on amber.

Well, 561 isn't yellow, but it has a yellow kind of tint to it, I sure wouldn't call it yellow with a green tint, but I realise either way of looking at it is correct, being in the middle between the two... OK, is this horse dead? I think I've been beating that horse for too long now. Here's a Duke Nukem plasma weapon using a lime green glow:




Paul, if you want to build a 561 nm CW laser let me know, I bought that 561 nm KTP crystal for 50 bucks, that was the same seller I purchased the Lumenis Nova Tri-Color laser from so he reduced the price from 69 to 50 for me, changing the sale to best offer, so I took it down. If you don't want it either way win-win, if you don't, I will.

Very nice visual. Yep, very close to 561nm that.
If someone builds a 561 I will be impressed and may look into it myself if the conversion efficiency is reasonable enough.
Good price on that KTP.

ultimatekaiser said:

My Melles Griot starts at 8500 and goes up from there at 10-15mW! I just sold a 5mW MG for about a grand ish.

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I was bidding on one of those a couple months back ... outbid, I think it went for $750CAD or thereabouts, couldn't justify going quite that high unfortunately.