build a laser using lg GH22NS40 DVD writer

[alx]

Hello laser experts.

I disassembled an LG GH22NS40 dvd writer and found 2 diodes:
- one round, which It has diameter size less then 4mm.
- one semi-round (like pictures attached). It has diameter 5.6mm (anyway, bigger then first one).

I tried to check booth. The first one is not working anymore (no light i can see). The second one (semi-round) is showing a nice red light when powered on using 2xAAA batteries (3V) but looks really strange (i can see inside it because it looks just a half one) and red light is not burning my skin at all!!

Questions:
- Which one is the DVD-Writer laser diode: the round one or the semi-round?
- if the semi-round diode is the desired one, its light SHOULD BE FOCUSED using some housing lens, like those on found on AixiZ home page in order to obtain a powerful beam laser?
- which housing from AixiZ will be ok: a 650nm 5mw 8mm X 14mm case $4.00 USD or 650nm 5mw 12X30mm case $4.50 USD.

Regards,
kkt

 

[Mohrenberg]

Re: build a laser using lg GH22NS40 DVD wirter

yes, the round one is an IR diode, you can't see that light, but it's there.

the "semi-round" is the long open can for burning lasers, now it's either not burning you because 1. it's not collimated with a lens, oe 2. you killed the diode by hooking it directly up to the batteries, and now you've got a pretty little red LED light.

if it's still shining brightly, then stop putting it on the battery, buy a driver and module.

 

[alx]

hello morenberg,

many thanks for clarification. So, we identified for sure my lg dvd burner diode. Yes, my semi-round diode is still working and is not dead at all I was confused due to instructions found here: www .instructables .com /id/Laser-Flashlight-Hack!!/
My round diode (IR diode) is looking like their DVD diode so i become worried because i have no light on my round diode. Now is clear: this diode is not useful anymore. Buy the way: on my round diode, i was able to read a code: 80Xp P12Y, where X is M or N letter and Y is 0 or D... Probably code stamped on it is: 80NP P120. Does anybody know to identify it? On semi-round diode, is not printed something, but is working.

On lg optical block (which contain booth diodes above) is printed in 2 places, the following code: 8120 0744 5692. I asked about this code on one electronics dealer and he said that cannot identify it, and the code should be something like: KSS210D for example, for a SONY optical block. Can somebody help me to identify correct code for this block? Also, on one small circuit on this block, is printed HI02 or H102. Thats's all printed on it.

Can you provide codes of other similar optical blocks in other dvd-burners, to ask my dealer? Maybe the optical block is cheap then etire dvdrw.

Question: attached scheme is good to be used with my laser diode? If i buy one Aixiz 650nm 5mw 12X30mm case $4.50 USD, driver is still required?

Regards,
kkt

 

[Mohrenberg]

hey i just got my DVD drive in the mail, SAME EXACT one your using,

this is regular LOC diode and will fit in an aixiz module, but the module only provides the lens to focus your laser along as serving as a small heatsink., and you still need a driver, i'm using rckstr's micro drive for mine set at 420mA, you can get them for around $11 on his site (unassembled).

 

[alx]

Hi mohrenberg,

Did you assembled? Which thermal power you got? Regarding your suggestion about driver, no problem ... I've already built it and made few minor changes to above posted driver schema (some resistors values has been recalculated and i added 2 more capacitors, to better protect LD and another one resistor to limit current into LD). Now, this driver should work with newer 22x dvd writer powerful laser diodes (see attachment) and drive LD up to 450mA (like i saw that other peoples said that could be ok). The 2.8 Ohm resistor value could be obtained very easy from two resistors in parallel 5.6 Ohm/0.25W - a standard value.

Now, remain just aixiz housing module. which one you ordered? can you take a look here www .mfgcn .com/_wsn/page2.html and tell me what to choose from:

650nm 5mw 12X30mm brass case $4.50 USD
635NM 5MW 3.2VDC $12.00 USD
635NM 10 MW 3.2VDC $30.00 US

Regards,
Alx

 

[alx]

Re: build a laser using lg GH22NS40 DVD wirter

the "semi-round" is the long open can for burning lasers, now it's either not burning you because 1. it's not collimated with a lens, oe 2. you killed the diode by hooking it directly up to the batteries, and now you've got a pretty little red LED light.

if it's still shining brightly, then stop putting it on the battery, buy a driver and module.

hey mohrenberg.

Today i received my aixiz module. I replaced LD with mine, grabbed from 22x LG writer. Bad news! I'M AFRAID THAT YOU ARE ABSOLUTELY RIGHT! Is unbelievable, how sensitive are this laser diodes. My laser beam has no power!. First i tried at 150mA, and put my hand 10cm in front of it. Nothing. I doubled current and tried again. The same ... just a nice red spot on my hand. Even focused, no power, just a small red spot. Tried more power, 410mA continuous 30 seconds. My hand doesn't seems to feel some heat but ... the aixiz housing become warm. No doubt, the driver is working, but my led NO!
I tried with my 650nm goggles:
- when look into aixiz spot 2m in front of me, i can see it (smaller then without goggles, but still visible)
- when my LD is used, I CANNOT SEE THE SPOT or the beam! Is so weak. Only without goggles is still visible!
And, if is matter, i measured internal LD resistance and is 19-20 Ohm!
I know that this LD have 3 pins, one of them not useful (for photo diode), one for dvd burner, and ground. Is not possible that now, by mistake, to power photo diode and not the laser one? I used pins and voltage as in picture attached.

Is this LOC working for you? I would like to know for sure if i was wrong when i choose to purchase this dvd writer, or when i powered my diode (just 2-3 times, less then 20-30 seconds each) by 2 x AAA duracell alkaline MN2400 batteries?
If diode is ok for you, i will buy again, the same DVD model and try again!

Question. For red LOC laser diodes, is normal that the beam (when is focused), to look like saturn planet (a very oblate ring having in the middle a spot) and not just a spot, like aixiz original module is revealing on the wall. It seems that on the wall, is mirroring the can at a small scale. I have attached a picture to understand how is looking my strong laser on the wall, 2 m in front of me )

 

[alx]

and here comes
- on the left: my oblate ring with spot in the middle
- on the right is spot produced by aixiz.
booth images, are visible on the wall, 2m in front of me.

 

[Mohrenberg]

yeah it seems your diode is dead.

even after you kill your diode, it will produce a very dim light that you can still shine on objects a few feet away.

if it's not incredibly bright....then it's not working.

 

[Spyderz20x6]

That'll teach you to listen to KipKay