BIG News: Green Laser Diodes

no need for a 500nm dvd burner...I think the app for most of these would be for hand held projectors.

I seen a cell phone on Dx w/ a projector on it looked nice...

Darkarmyofone said:

VERY interesting! too bad theres no ACTUAL photo of the diode...

I'm NOT calling ANYONE a liar, but that could be an 0-like module in a steel box... BUT I HOPE IT ISNT!! lol

I'd kill for a pocket mini TRIO, i've got red and green "300mW & 400mW+" now alls we needs is green ^_^

But i'd settle for turqouis!

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Don't worry, it's not fake. This is a multi-million dollar corporation participating in a billion+ dollar market making the biggest breakthrough in well over 2 years. They're not faking it, there's too much at stake. And, the paper is out now, and everything matches mostly what it should. And, there's a photo in the full paper, and if it's a DPSS system, it's the crappiest DPSS system I've ever seen.

FireMyLaser said:

'bout fickin' time!

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Hey, this stuff is harder than it looks . The full paper is posted now, it's in Applied Physics Express (in case anyone has a subscription at their institute of higher learning).

Just to show how difficult/bad these things are (being first ever produced and all) and how much work has to be done, they gave the LIV characteristics of some of their diodes. The 531nm diode had a threshold current of 924 mA. Yes, almost a full amp of current before it even turned on. For their 520 nm diodes, which they say was about average with their new process, they give the threshold current as 491 mA, and a threshold voltage of about 18 V. Remember, a PHR has threshold at about 25mA & <5V, so that just shows how much work i9s still to be done. At 1240mA, well over an amp, they were only getting 28mW of power out of these things.

They did grow on semipolar GaN, for anyone into that stuff and who can understand what that means.

Crazy stuff. Very exciting, and a lot more work to be done.

Wow, 1A!

If it stays like that we are gonna need new LD drivers...

1A is nothing, many diodes (60W) require like 40A just to get to their lasing threshold

Most LM317 drivers can handle over an amp, flexdrives can too IIRC, aswell as the flexmods (6A)

Pretty cool, but they will not be cheap any time in the near future, since optical drives already use the lowest wavelength possible. Only application for these right now would be laser TVs, portable projectors and us hobbysists.

Engineering samples, knowing Nichia would be well over $2000 apeice.

^Yeah, but 1.2A for 28mW is a bit much.. not to mention that's 1.2A at ~18V. Also, there is a new holographic disc storage platform in development that is shooting for a 6TB maximum capacity (currently at 500GB max..). Utilizes 1W of green and an unspecified amount of blue laser light. The whole thing is very much still under development, and a major holdup is a lack of high-powered green diodes. DPSS is nowhere near stable enough.

Re: Laser TV's... Won't that still require a DPSS for blue, or is 405nm OK for that? I'm just assuming 473nm would be better....?

There are 445nm blue diodes readily available..

^Yep.

These green diodes are made on basically the same materials system as violet diodes, InGaN/GaN. This materials system can be adjusted/used for EVERY wavelength between some minimum and maximum wavelengths. Until this paper, the maximum wavelength was 514nm. Now the maximum proven, working diode is 531nm, so you can make a diode with any wavelength between 405 and 531, just by changing how you make it. (And 405nm isn't really the minimum, it can go lower, but I don't off the top of my head know how low in wavelength working laser diodes have actually been made). Blue has been around for years, but it is only now that they have pushed the maximum possible wavelength up into the green wavelengths.

omg!!!! this is a BREAKTHROUGH!!!!

ElektroFreak said:

There are 445nm blue diodes readily available..

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Where can I get one of those!!?!?! :yh:

iknitsteel said:

Where can I get one of those!!?!?! :yh:

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If you've got a couple grand laying around, there are several places. They're very available, they're just not cheap.

IIRC, there was a poster in the Blue/Yellow/Other section thinking of getting some blue diodes to sell and was checking interest levels. I seem to remember him being able to get them for a few hundred bucks in quantities over 100. You might try searching there to see if he ever decided to buy any and resell them.

iknitsteel said:

Where can I get one of those!!?!?! :yh:

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Here: http://www.nichia.com/product/laser-main.html

but be prepared to have to sell a lung, and maybe also an eye (lol) ..... they are not exactly cheap

btw, they sell also 473 and 488 nm, and a nice 500mW 453 nm unit (but very unstable, look at the current range they give fot it)

You certainly don't have to go through Nichia. You can buy complete lab-style units for laser shows from Kvant here: Diode Lasers - laserShow.sk KVANT ltd.

Check out the datasheet for the "BLUE series"

You'd actually end up paying MUCH more from Nichia.

Uhm, i'm not saying that they are publishing wrong data, but reading their specifications .....

4 W CW at 445nm DIODE ? ..... with a beam 4 x 4,5mm size and a divergence on slow axis of 0.2 ? ..... wondering where they found this "diode", that with those data, for me looks a bit more similar to a custom chips pattern (probably TEC-mounted) with a prefocusing optic group, more than a single diode ..... or, maybe, a fiber-coupled array of single diodes ( wondering if they have assembled something like 8 x NDB7112E or similar with fibers, LOL )

Too bad that they never post pics of the inside of their products ..... i may be happy to see a good macro of this "diode" assembly .....

It is Kvant.. I have no idea where they get their diodes, but I trust their specs completely. I would almost guarantee that any 4W 445nm blue diode module would almost have to be multiple diodes, or multimode at the very least.

Actually 514nm isn't turquoise, it's green. I have an argon that's a 514nm SL, and basically when you compare that to the standard 535nm, the 535 is a little more lime-greenish and the 514 is a cooler shade of green, like a jade green.

The 514nm is the bottom dot here in the pic:
http://onfinite.com/libraries/1449092/4e8.jpg

Now, 500nm would likely appear to be sort of an aqua colored beam, but not quite as blue as a typical argon, roughly half-way between a blue line argon at 488 and 514 green.

As far as having any of these colors available (and by that I mean priced on the order of 405nm diodes at similar powers) for pointers I'd choose 488nm. To be able to carry around that beautiful argon blue-green would be utterly awesome. To go from a 40lb laser system to something that fits in a flashlight case would be an awesome breakthrough - and if it's priced the same or less than a typical used argon on Ebay!