Newbie Question; why write speed for blu ?

[JBTexas]

I've noticed in this section, and Buy/Sell/Trade, etc., that people use terms such as 12x and 16x in conjunction with blue lasers; is that the write speed that the diode was designed for? (from, say, a Blu-ray burner?)

If so, why is that important (enough so that it is mentioned frequently).

To a newbie like me, a laser diode's power output, duty cycle, wavelength, current draw, stability, etc. would be important; but why write speed (IF that is what is meant by 12x, 8x, 16x, etc., why is that important from a laser hobbiest's point of view?)

... Thanks

 

[Bionic-Badger]

Generally the faster the disc burner, the higher power the laser must be in order to be able to achieve that burn speed. This isn't always true, as other techniques such as improved optics can increase the burn speed, but in general the burn speed rating is reflective of the power of the laser diode inside.

 

[JBTexas]

Thanks for the answer... and then I guess I can see why, if people are scavenging from burners, why the blu diodes would be specified via burnspeed rather than output (maybe the output isn't known (at the time), but experienced people can get an idea from the known burnspeed).

 

[Eudaimonium]

First of all, you're mistaking if you're calling Blu-ray diodes "blue". Wavelenght emitted is around 405nm average, (from 400 to 415nm but it's generally accepted as 405nm diodes) and to a human eye appears very deep violet shade, sort of like those blacklight tubes at nightclubs just more violet-ish and less blue-ish.

Next, Bluray diodes can be found as several standard "recognition names":
PHR - Those diodes come from PHR-803T sled which is found inside Xbox 360 HD-DVD drive addon. Although only a reader module, diode is capable of producing 100mW and maybe more with quality lens.
GGW- Coming from 6x Bluray Burner sled called GGW-H20L , they can (or could, at least) spew out some 200mW.
SF-AW - Sled's full name is SF-AW210 and these diodes are generally accepted as 150mW
8x - Bluray sleds from writers capable of giving 8x writing speeds on bluray discs, one very common sled is BDR-203 . These diodes can go up to 400mW
12x - can come from variety of sleds, two most popular ones being BDR-205 and SF-BW512 sleds (notice very similar names to those sleds up there), and can reach up to 500-600 mW, depending on diode efficiency, lens, heatsinking.

Hope that clears stuff up for you.

Also, 445nm diodes are not violet diodes, they are actually blue diodes and capable of spewing out powers of 1.5W calibers. Which is incredibly dangerous and powerful. They come from C@sio projectors (don't use full spelled name of the company on the forums).

There.

Any further questions, feel free to PM me and ask away

Have fun.

 

[JBTexas]

Eudaimonium;

Very informative, thanks!