New Record - 499.8nm CW

http://www.semiconductor-today.com/news_items/2009/FEB/ROHM_230209.htm

Non-polar InGaN lasers near green light

Scientists at Rohm Co Ltd’s R&D headquarters in Kyoto, Japan have extended the wavelength for continuous wave (CW) operation of indium gallium nitride (InGaN) laser diodes (LDs) [Okamoto et al, App. Phys. Lett., vol.94, p.071105, 2009]. The researchers claim that the 499.8nm (near-green) CW lasing wavelength is the longest reported for such devices. Previously, Rohm reported a 481nm blue-green laser last June followed by a 488nm laser in October, while Nichia had reported a 488nm blue-green laser in January 2008. Among the possible applications of laser diodes emitting at green wavelengths (i.e. 490–560nm), when commercialized, could be full-color displays and mobile projectors.

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The goal is 520nm, or thereabouts, and they're getting close over there at Rohm, it sounds like. I've seen the full article (I forgot what journal it was in, I think it was APL though), and their numbers look pretty good. And, the journal article with the 499.8 result was submitted a couple months ago, so who knows what their current devices are doing. Pretty interesting though, we'll see what happens in the next couple of months, it should be an exciting time. Green laser diodes look to be getting closer everyday.

Green laser diodes sound yummy.  

If they ever make one your wallet might weigh quite a bit less  :'(

*waits ten years* oh look green laser diodes for sale 20 bucks.

Interesting stuff - i wonder how long it will take for these things to be commercialized. Perhaps we'll look at the current dpss lasers as awkward complex things in a decade?

If i were you id place an anti static bag on my laser and store it for years

It's great to see them approaching green, although those 488nm diodes are probably really pretty.  I wonder if there might be a market for diode replacements of the argon-ion.

488 has already been available for some time now in DPSS.

DPSS is probably too expensieve for mass market applications though, even 473. If affordable green and blue diodes hit the market, mainstream applications will be plenty.

Can't wait!!

Can't wait till the "Laser CPU" gets built either

Niko said:

Can't wait!!

Can't wait till the "Laser CPU" gets built either

Click to expand...

just waiting for a light transistor

Awesome!

To be honest I wouldn't actually mind having a 499nm diode. I would guess this would be a dark greenish blue?

499nm is a very pretty color http://www.laserpointerforums.com/forumdata/yabbfiles/Attachments/spectrumchartv10.JPG

It is a pretty color, just not suitable as the green component in RGB projection, which i suppose is the application goal of this research.

^Correct, RBG laser projectors.

You can see from this chart why you need 520 instead of being of at 500nm. If anyone doesn't know how to read these, it's fairly simple: it's a color mixing chart. Pick any two points on the outside edge (single wavelength colors), and a line connecting those two points shows all the possible colors you can make by mixing different amounts of those two colors. For instance, most everyone here knows you can mix red and green to get yellow, and that's readily apparent on the chart.

Pick any 3 colors on the chart, and the triangle formed by those those points encloses every color that can be made by mixing those 3 colors. Of course we already have red diodes around 650, and blue diodes in the 450 range. To get the most possible colors then, we want to make the green at about 520nm to get the widest gamut possible. By comparison, 500nm is the dot on the left edge that's just above .5 on the y-axis. Using this color would practically wipe out all yellows and green, so you'd have no yellows or greens on your TV. But get to that 520nm, using the ~650 and ~450 we already have, and you have practically the entire gamut of colors, and your triangle is actually then bigger than LCD or plasma either one.

So you have more colors, the possibility for smaller pixels, higher energy efficiency, a smaller and lighter-weight TV, darker blacks (no backlighting necessary unlike LCD), and overall just a better TV in every regard.

Benm said:

Interesting stuff - i wonder how long it will take for these things to be commercialized. Perhaps we'll look at the current dpss lasers as awkward complex things in a decade?

Click to expand...

I would say that DPSS lasers for RGB display applications and light shows will become a thing of the past quite quickly once green and blue diodes are easily and economically obtainable. DPSS lasers are inherently very unstable, and require a good deal of other electronics and parts to make them even close to as stable as diodes.. Compared to laser diodes alone, DPSS technology is ungainly and awkward.

One major reason to keep DPSS around will be for the scientific and professional community. The beam quality of a well-made DPSS laser is far better than a diode, although this can be corrected with optics to a point.

Crossfire said:

It's great to see them approaching green, although those 488nm diodes are probably really pretty.  I wonder if there might be a market for diode replacements of the argon-ion.

Click to expand...

You know what that means! Lots of Argons for the hobbyists!

When will it be the time when I will be able to go to a store and ask for 500nm, 600nm, 437nm and 532nm diodes? :'(