TRUE green laser!

[ThunderBird89]

I've checked now, and still haven't seen this posted by anyone else (unlike the laser ignition plug messup...).

Japanese scientists claim to have created the first LD which puts out green light, without a frequency doubler crystal. It operates at 531nm right away, from a GaN crystal engineered to prevent the output drop that comes with increasing wavelength on this crystal.

Here's one article: I-Micronews - COMPOUND SEMI OPTOELECTRONICS: Sumitomo claims the world’s first green laser diode on bulk ...

And here's a Slashdot link that provides some more sites: Slashdot | Finally, a True Green Laser

 

[bobhaha]

This is awesome.. just wondering how much these will be once released into the market :thinking:

-Adrian

 

[themandalorian]

Kinda old news search it! Very cool though! No more intricate DPSS lasers, well not for years at least

 

[ElektroFreak]

There are already two other threads discussing this..

 

[pullbangdead]

This is awesome.. just wondering how much these will be once released into the market :thinking:

-Adrian

The answer to that question is one big "depends". And it depends on a LOT of things.

Actual manufacturing process is relatively the same as violet lasers. Yields (meaning percentage of fabricated lasers that actually work), especially at first, will be lower than violet, but the process is the same.

One HUGE cost difference comes in the substrate, and the limitations that come with the substrate. All the current violet lasers we get/use are grown on c-plane GaN, whereas these are grown on semi-polar GaN (20-21, to be exact). Basically, all GaN substrates get sliced from cylinders. The cylinder has a 2-inch diameter, and a height that likely maxes out around 5mm or so. For c-plane growth, you use the circular face of the cylinder, so when you slice the cylinder into substrates, you get very thin circular wafers that are 2-inches in diameter. However, when you use other planes, like these green lasers, you have to slice that cylinder in a different direction. For 20-21, I think that slice is 75degrees off of the big, circular face, so the wafers you get are TINY, only ~5mm wide instead of 2-inch diameter circles, and of varying lengths as you slice across the cylinder. You'll get one wafer that is 2 inches long, but the rest will all be shorter, going all the way to 0.

So with these lasers, the wafer is a tiny fraction of the size of the wafers used for violet lasers, but the process is the same, so you get MANY fewer lasers per wafer than you get with violet, so the price has to be MUCH higher. Also, those little bitty substrates are more expensive because they're more difficult in general for substrate makers to work with.

Any of that make sense?

 

[Snotface3]

I even heard that they are trying to make lasers go at 5 miles per hour. Interesting concept for light to travel that far.

 

[BrewCityMusic]

Good Explaination, PBD!

 

[bobhaha]

@pullbangdead thank you for the explination.. but just think back a half year... Blu-ray burners were $1200 (not sure how much the sleds were) but this proves that if a gree-ray burner came out (which is almost as good as a blu-ray and ofcorse better then a normal dvd burner) can you imagine the prices? These "green-ray" might replace dvd burners and might become the norm!

-Adrian

 

[HIMNL9]

^ sorry for contradict you, but green is a wavelenght more long than blue ray ..... if you mean, for maximum storage on the media, you need to shorten the wavelenght, for increase the density of the data written on the disk (well, i remember when paying like 600.000 lit (almost 300 euro) in the first times for a 2 x cd writer, and was a marvelous thing to have it on your pc at home, cause first only industries was able to write on cd's ..... and now, i hear sometimes peoples, in the shop, that complain for have "only" 25 Gb on a blue ray disk, LOL)

anyway, if the market still go in the direction of increase capacity of the disks, you can expect something like "UV disks" with 500 Gb on 4 layers, and diodes with an output of 220 nm or less

 

[nikokapo]

^ sorry for contradict you, but green is a wavelenght more long than blue ray ..... if you mean, for maximum storage on the media, you need to shorten the wavelenght, for increase the density of the data written on the disk (well, i remember when paying like 600.000 lit (almost 300 euro) in the first times for a 2 x cd writer, and was a marvelous thing to have it on your pc at home, cause first only industries was able to write on cd's ..... and now, i hear sometimes peoples, in the shop, that complain for have "only" 25 Gb on a blue ray disk, LOL)

anyway, if the market still go in the direction of increase capacity of the disks, you can expect something like "UV disks" with 500 Gb on 4 layers, and diodes with an output of 220 nm or less

Great thing that they didn't release the GR-D (Gamma Ray Disk)

 

[HIMNL9]

Great thing that they didn't release the GR-D (Gamma Ray Disk)

No, they decided to not release it, after that little accident happened during the first tests (hulk, remember ?) ..... :crackup:

 

[bobhaha]

^ sorry for contradict you, but green is a wavelenght more long than blue ray ..... if you mean, for maximum storage on the media, you need to shorten the wavelenght, for increase the density of the data written on the disk (well, i remember when paying like 600.000 lit (almost 300 euro) in the first times for a 2 x cd writer, and was a marvelous thing to have it on your pc at home, cause first only industries was able to write on cd's ..... and now, i hear sometimes peoples, in the shop, that complain for have "only" 25 Gb on a blue ray disk, LOL)

anyway, if the market still go in the direction of increase capacity of the disks, you can expect something like "UV disks" with 500 Gb on 4 layers, and diodes with an output of 220 nm or less

Yes I know that.. but dvd burners use red laser.. which has longer wave length then green... so in that case "green-ray" would be a better burner in regards to storage capasity etc..

Btw I didn't say that "green-ray" was better then blu-ray I said it was almost as good as... because if we were comparing red and blu-ray red is ~600nm where blu-ray is ~400nm... but green has ~530nm so as you can see it is in the middle of the two... this is why I said that there is a possibility that this could become the norm!

-Adrian

 

[pseudolobster]

I even heard that they are trying to make lasers go at 5 miles per hour. Interesting concept for light to travel that far.

I'm not sure what you're saying... 5mph is 134 million times slower than it normally travels... and as far as light traveling long distances, well, look to the night sky.. the light you see coming from stars has traveled trillions of miles... As far as slowing light down, this isn't anything spectacular, shine it through air or water or anything else and it's going much slower than it would in a vacuum.. a decade ago scientists were able to slow light down to walking speed, so 5mph doesn't sound like a big deal. Also I fail to see what this has to do with lasers, specifically green laser diodes.

 

[chipdouglas]

@bobhaha. yes green is better at it than red. but violet tops that and shorter wave length tops that etc...etc... but i read that scientists are workin on a halographic drive that stores info in tera bytes on a disk.

 

[Cyparagon]

I even heard that they are trying to make lasers go at 5 miles per hour. Interesting concept for light to travel that far.

If by "that far" you mean "that slow" and if by "lasers go at 5 miles an hour" you mean "laser light go at 5 miles an hour," It's already been done. They use sodium clouds chilled to almost absolute zero. I saw it on "the universe" documentary series the other day.

if you mean, for maximum storage on the media, you need to shorten the wavelenght

Not for the holographic disks proposed. They were going to utilize 1W green lasers.

 

[HIMNL9]

If you mean slow down the light speed, U S navy is experimenting about this from a lot of time, with different combinations of lenses, materials and fluids/gas chambers, for weaponry purpose .....

I mean, it's elementar physic, after all ..... you can't destroy energy, right ? ..... so, if you slow down the speed of the light, you increase proportionally the energy delivered at the target point.

Just imagine to achieve a lens combination that slow down the light speed, also just of 1 million times ..... the resulting energy at the target point becomes 1 million times more, cause the photon flux in the beam is 1 million times great ..... like, starting with a 50 mW green pointer, and ending with 50 KW green dot, LOL :drool:

Not speaking about the scenic effect ..... if the light travel slow enough and you move the emitter fast enough, you can see the beam curve and wave in the air, ROTFL