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LG 22x, how to get 500mW red?

Krutz

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class IV blu-ray handhelds are now almost common, with several built and working.. how about a new red diode which would be up to that too? the LOC is around since years, i think its said to be the 16x or 20x LG drive?
i got me two LG 22x drives, one is in my computer, the other one is.. toast!
the diode looks just like the regular LOC. the sled is all different, though.

after a 405-g1 lens:

468mA - 330mW
500mA - 357mW
604mA - 408mW
705mA - 443mW

i turned the laser off (flexdrive), on again at 705mA, instant LED. the current rose to 725mA.
I was sure it wouldnt survive this, but just had to try.. and, almost class IV! :)

just to compare, i then installed a regular LOC:

369mA - 280mW
391mA - 298mW
505mA - 360mW
521mA - 370mW
725mA - 437mW

real sensitive pot, at the end, i didnt really want to turn it up that high.. ;-)
i set it back to 360mW at a half amp current.


so it seems like a few LOC may stay alive at 500mW, but that cant be reliable, and with many casualties on the way.. how about an alternative? lets do a fund, buy one, two of the available drives and check their diodes? even if there is no source for the sled, i would immediately buy a few whole drives to get a single-diode class IV laser..

and wasnt there someone who has a new sled, part-number similar to our LOC, but a bit higher? still untested, with no graphs yet?

manuel
 





Krutz

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good thinking, meatball! its a big difference if its dvd-r or dvd-rw or doublelayer, so perhaps theres stronger and faster stuff out there that is limited to 24x dvd-r because of the spindle-rotation-speed?

will have a loom later!

manuel
 
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why are you using a 405 ar coated lens for reds? you actually lose some power i think. you need a broadband coated or ar coated for red to get the best results.
 

Krutz

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the red-ar-coated lenses have only a few % gain over this 405-g1 one, but have a farther focallength. so i willingly traded a few % for a tighter beam and higher powerdensity of the collimated beam. its still quite much stronger than my red-ar-coated acrylic from virtualvillage, i gained something around 30mw with the new lens..

manuel
 
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im not sure if he still carrys them but larryDFW had a bad-a$$ broadband coated lens that gave close to 25% increase in power.. works great for BR too...
 

Benm

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Just looking at those current vs power numbers in the opening post, is there any reason to assume the diode is different? As you said it looks like a 'regular' LOC diode, and it seems to perform identically in terms of current/power plot.

The difference in speed might be just the mechanics of the drive as pointed out earlier. One clear indication of this would be any drive that has the same maximum speed for reading and writing: When reading the laser power is not the limiting factor, so it must be either mechanical or in the processing electronics.
 

Krutz

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hmm, dvd drives seem to be pretty much stuck now.. a few do 24x singlelayer burning, but i wouldnt count on that.
what i found, though:

Samsung SH-S202N (BEWE/BEWN)
Samsung SH-S203D (BEWE/BEWN)
Samsung SH-S203P (BEWE/BEWN)
different colors, they all are
20x/8x/20x/6x/12x/16x DVD+R/DVD+RW/DVD-R/DVD-RW/DVD-RAM/DVD-ROM • 16x/12x DVD-R/DVD+R DL
the description says 16x dual-layer. theres a hundred which do 12x dual-layer, but these are the only ones who do it faster.
around 30€ in germany

LiteOn iHES208
8x BD-ROM • 16x/12x/16x/12x/12x/16x DVD+R/DVD+RW/DVD-R/DVD-RW/DVD-RAM/DVD-ROM • 12x/12x DVD+R/DVD-R DL
everything 12x or faster, the only one who does dvd-rw at 12x.
over 100€ here.. *sigh*
available since 16.04.2009.

that seems to be the end of dvd and high-power reds..

i tried a good while, but couldnt find the thread where a new sled was mentioned. something like "lpc 817", one number higher than the regular LOC.

manuel
 

daguin

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There hasn't been much reason to continue to try to get more and more out of the red diodes for DVD writing. Violet is the new technology. Keeping reds in there are simply to keep them backward compatible and for the market to catch up.

Some of the new sleds are apparently utilizing the new 3.8mm red diode for writing DVD's. They have not yet been tested much by us. Just like in the market, the focus here has been on violet.

Peace,
dave
 

Krutz

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flaminpyro: the 9mm ones are multimode, at least i never heard of 9mm singlemode reds, or any other high-power singlemode and affordable red diode other than out of dvd drives ;-)
are you talking about herursciences' diodes?

i'd rather have a 500mw singlemode than a one watt multimode.. for now, at least.. ask again later ;-)

manuel
 
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why are you using a 405 ar coated lens for reds? you actually lose some power i think. you need a broadband coated or ar coated for red to get the best results.
Those 405nm coated lens that Jayrob and Larry sell are still a decent amount more efficient than an Aixiz acrylic (and maybe even Aixiz glass) for red.


I really don't see us getting 500mW with a decent lifetime out of these, but it doesn't hurt to try. I would even be happy with 400mW, but in the past nobody had luck at 400mW with the open cans at the time. Maybe one of the 22x drives will be able to withstand 400mW for a while.

What Daguin said is pretty true, DVDs are slowly becoming obsolete so there is no need for companies to waste money and time developing faster drives, but the good thing is that DVD burners will be really cheap pretty soon.
 

Benm

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I think DVD is mature as a technology, no breakthroughs in speed and hence laser diode power is to be expected anymore. We'll just have to get the best out of the trusty LPC diodes as they are, perhaps combine two if you must get into class IV.
 
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I also think DVD writer speeds maxed out @ 24X.

Even new BR drives write DVD's at 16X.

A few of the laser diode manufacturers are working on higher speeds for dual-layer.

They look for new markets to sell their diodes.

I do think with the right diode & AR coated lens we can hit 500mw.

There are some 1/2 watt Reds available. A guy on Photolexicon is combining 4 LPC diodes.
4-Diode Combiner

Misterwilling has a 560mw Red that I am helping to optimize the lens system.

LarryDFW

P.S. A Hi-Power lens AR-coated specifically for Red, will add 3-10% more power,
depending on the comparison glass lens.
 
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