watch a dvd-burner burn.. dvds!

[Krutz]

so you got a 300mw+ red laser out of a 20$ dvd burner. ever asked yourself, why the heck they have such strong lasers inside? do they even use them to any extent?
i wondered too. and, in my past life, i was an IT guy, with pimped up computer and all.
i cut me a hole into my case to watch my ancient dvd-rom totating dvds. i just exchanged it for a 22x dvd-burner. guess which one - why, an LG 22x of course! ;-)
before even installing that drive, i cut a window into it (again).
here you have it, the first computer you can watch burn dvds, or, if you prefer, let do eyesurgery to you!

 

[Krutz]

thats the whole. the old scorpion's tail logo is from back then, ancient. who recognizes the symbol?

 

[Krutz]

watching inside, with no media, to see the sled do its work

 

[Krutz]

when you close the drive without media, the sled goes to the inner circle of the (non-existant) media, and tries to find something with IR and red laser. dont worry, its (guessed) not more than 5mw, and *so* divergent that you cant do harm with it. the focus would be at the dvd, thats 0.8mm above the lens, way under the acrylic window. it spreads to several cm² quickly. and, finally, it "blinks" only for less than a second, before the sled hides inside again.
still, nice effect!

 

[Krutz]

here we go. dvd-reading, full pic. you barely see the really tiny, and quite dim dot.

 

[Krutz]

same while burning a dvd. i burned this one with 12x, for datasafety. these media are up to 16x only, anyway.
you see a distinct raise in brightness. but, well, does this look like 200+ mw? stay tuned for the answer!

 

[Krutz]

closeup of reading-mode..

 

[Krutz]

..and writing-mode..

 

[Krutz]

hmm, with the new dvd-writer, and habing made a dozen changes to my linux-configuration, i cant read the dvds i burned. but thats a different story for a different forum. at least i can verify there was some laser-light involved! ;-)

next question: what does the dvd make with intense laserlight shined from the underside?
here i shine my ~200mw collimated laser on its underside, looking onto the upper side. so, there isnt much light making it through at all!

 

[Krutz]

here i cover the dot half with plain paper. you see that no light makes it through the dvd and paper, its almost nothing coming through. on the pics it looks brighter than in real, it really isnt much. you cant even see red when holding the paper above it and watching the papers underside where the laser "shines" on..

 

[Krutz]

hmm, why not forget the whole burner, which didnt write my dvd properly anyway, and burn by yourself? here i focus my 200mw pointer as tiny as possible on the dvds underside. yes, the burner focussed smaller! it wasnt that easy, to hold a laser, a lens, a dvd and a cam, align everything, all that with closed eyes! dont do that at home! reflective surfaces and high-powered lasers dont mix well without lasergoogles!
..and voila, the selfmade-dot isnt exactly the same as the burner-in-action-dot, but somehow comparable!

 

[Krutz]

the underside of said dvd. the part where i "burned" on was still empty, dvd-writing-wise. the marker-markings burned away easily, with a bit of smoke. but for the dvd itself, not much happening. the color-change looks similar to the written surface, lighter color.
i planned to burn the written datapart of this dvd, but it wasnt readable to begin with, as i wrote.

new idea: burn nice images onto cds or dvds! but this definitely only with googles! you *will* blind yourself in the first 5 secondy trying this without googles!

 

[Krutz]

i ordered two of those writers, the second one will be the donor for my next laser.
i tried to see the IR with my cam, but nothing. remember how much the media absorbs? thats what its supposed to do, actually! ..and then the IR-filter in my cam, nothing left visible.. perhaps i'll look with my webcam where i removed the IR filter.

thats it, hope you enjoyed it! questions? want a closeup of any of the pics? let me know!

manuel

 

[Viracocha]

so you got a 300mw+ red laser out of a 20$ dvd burner. ever asked yourself, why the heck they have such strong lasers inside? do they even use them to any extent?

The obvious answer (which means it's probably wrong) is that, as the data rate for burning increases, the number of pulses a second also goes up. This makes the duration of each pulse shorter so the power of the laser needs to increase to compensate for this.

Would be great if they made a 100x dvd writer as they'll probably need to use a tiny 2W+ CO2 laser with blanking! Now that would make a fun pointer! ;D
(they won't use CO2 because the wavelength would be far too large, but a boy can dream)

p.s. Is that symbol NOD? (classic game )

 

[Krutz]

you are right, KANE LIVES!

hmm, i guess 22x dvd is about the end.. i was surprised to see anything higher than 16x actually! the limiting factor being the rotation of the media, therefore there isnt anything higher than 52x cd.. except that one drive which used more than one laser/pickup/sensor or whatever. it was more than 52x, but with the same rotational speed.
any higher, and cds just explode. and sometimes do already..

manuel

 

[sad_sagi]

how about those light-scribe discs? maybe the top of those would be easier to doodle on with a laser.
I've tried burning cheap cd's with my red lazor and found it quite hard, and in the end all you do is melt the thin plastic label which has the "data" sheet on the bottom...