Direct green laser diodes/modules?

ebay,

$5 with free shipping from China. Or you can get a 50mW for $18.

Be very careful with Green !!, you CAN put an *eye out*, and 5mW is too much, if you look at the safety specs, it says 5mW at a

1/1,000 duty cycle, NOT 5mW continuous !!!! (as they make in CHINA)

50mW will dammage your retna off reflected light

USA Laser Product Regulation 21 CFR 1040.10

On a sunny day (Fri, 08 Jul 2011 17:58:43 +0200) it happened Richard Rasker wrote in :

Yes I have read some laser projector manufacturer uses a direct green laser. Why not ask them?

.

sed

15 a

if

.

I only know of red's up to ~635nm and then blues at ~405nm.

George H.

Coincidentally (?) there's an article in this week's EDN (as well as others in the trade press) about a true green laser from EpiCrystals.

--
Rich Webb     Norfolk, VA

The other thing to remember is that cheap green YAGs put out very significant amounts of 808 nm and 1064 nm as well. If your laser goggles aren't opaque at those wavelengths, they'll give you a false sense of security.

I usually use a germanium photodiode to measure goggle effectiveness, for that reason.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net

put your eye out with this one;

$5.90 and free shipping (still damage eye too)

the front comes off and you have the module

Green is good for ocean penetration

--
Dirk

http://www.neopax.com/technomage/ - My new book - Magick and Technology

I already did extensive (re)search on eBay and laser manufacturers' sites, but unfortunately, all these are the pumped IR-types I already described. My main problem is the very limited operational temperature range (15-35 degrees Celsius), which is exceeded in all sorts of climates and environments. At 10 degrees Celsius for instance, there's hardly any green output any more, but still a huge amount of IR -- in fact far more than at the optimal temperature, because the green light feedback circuit drives the IR laser diode to its limits.

Sure, I can include a Peltier element and some extra control electronics to keep the laser at the optimum temperature, but I'd very much like to do away with all the hassle and use a true green laser diode.

Richard Rasker

--
http://www.linetec.nl

The green in "pico beamers" comers from blue lasers irradiating a blue-utilizing green-fluorescing phosphor.

I have heard of green laser diode laboratory prototypes. IIRC, the wavelength was around 515 nm, a very slightly bluish shade of green.

--
 - Don Klipstein (don@donklipstein.com)

~405 nm appears to me as violet. I have one.

There is a recent blue one at ~445 nm. A friend loaned me one.

--
 - Don Klipstein (don@donklipstein.com)

Oh, I've barely used the reds and never blue. I just pulled the Thor labs catalog off the shelf. The blue seem much too expensive.

George H.

On a sunny day (Fri, 08 Jul 2011 17:58:43 +0200) it happened Richard Rasker wrote in :

It is microvision:

They have development tools too.

--
Dirk

http://www.neopax.com/technomage/ - My new book - Magick and Technology

I took a look. This turns out to be for smaller projectors than I was thinking of.

Also, evaluation kit costs $2K, development kit costs $2.5K.

Microvision reports use of direct green in prototypes, posted 1/25/2011:

Mentions that the usual way is conversion of infrared to green (which usually means 532 nm).

--
 - Don Klipstein (don@donklipstein.com)

--
Dirk

http://www.neopax.com/technomage/ - My new book - Magick and Technology

That says that green diode lasers ("direct green") will be a major breakthrough, once they are actually practically achieved.

They mention a prototype that wasn't very good - it barely worked and only achieved decent efficiency in some pulse mode.

Wavelength range mentioned was 520-531 nm, which is, "in my words", greenest of mid-green. 520 nm has some significant blue visual stimulation.

The usual color video display standards specify a "green primary" that is yelowish. For example, sRGB and NTSC green primaries have "dominant wavelength" around 550 or in the upper 540's of nm. My guess is that yellowishness of a green primary is tolerable while bluishness is not. Of course, a shorter-wavelength narrower-bandwidth green primary can be changed to approximation of sRGB or NTSC green primary by having some percentage of itself added to it from the red primary - as long as it is not excessively bluish. (Then again, I see this as doable with green wavelengths even as short as 525 or 520 nm.)

So, I see the main obstacle being producing laser diodes of wavelength

520-550 nm, able to run continuously (as if the display is of a lawn or a forest or full-blast white or yellow), and such laser diodes actually being economically practically in production.

Maybe only another year or 2 ...

--
 - Don Klipstein (don@donklipstein.com)

Hmm, so I'm wrong, and there are indeed no green laser diodes available, commercial or not. Well, I guess that answers my question. Thank you, and everyone else who took the trouble to reply.

Richard Rasker

--
http://www.linetec.nl

Yeah, I've been looking for greens, too (red isn't good on LCD or plasma screens). I'm quite leery of the pumped ones. The boss wants one, but I don't think he understands the product liability risks built into these things.

Hmm, so I'm wrong, and there are indeed no green laser diodes available, commercial or not. Well, I guess that answers my question. Thank you, and everyone else who took the trouble to reply.

Richard Rasker

--
http://www.linetec.nl

Toptica Photonics is advertising a 515 nm green laser with what they call 
"direct diode technology", see 
http://www.toptica.com/pr_news/news/news_single/article//toptica-presents-515-nm-direct-diode-technology-live-at-photonics-west.html 
.

I would be surprised if it were truly directly from a diode laser.

Bret Cannon