# Pics of harvesting a DVD burner laser diode :D



## liveforphysics (Jan 19, 2007)

Well, one of the high speed DVD burners that I ordered arived today. It didn't last 5mins before I started takeing it apart. I was kinda suprized to see open type laser diodes, but after talking to an optics specialist buddy, he told me that the open cases are able to cool better and tend to work better in high power situations. The downside of course being that a couple of dust particles in the wrong spot will damage/destroy them.

In total, I spent about 10mins total to get it all apart. It only took that long because I was being really careful on the first time. If I needed to do another I could easily see ~5mins for removal.

So, here are the pics.
































This little guy appears to be the photodiode that receives the changes in laser reflection intensity into bits. Via a very clever prism/partial mirror setup, there were 2 of these little guys, I'm assumeing 1 for the DVD reading and 1 for the wider CD reading.






Now, I wont know until I get home and apply some power to this little guy, but I belive he is the whole purpose of the death of a DVD burner. Note the open case design. 





















So, the package appears to be the t56 (5.6mm) open type LD package. The leg that could connect to a output sensor is not connected to the attached ribbon cable. This means output is likely monitered in a more precise way. 

When I get home, I will apply some power and see if I get visible spectrum light. I will keep you guys posted.

-Luke


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## Ledean (Jan 19, 2007)

Cool pictures.
Waiting to see it action.
How much voltage are you going to apply to it ?


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## Mawaii (Jan 19, 2007)

Looks exactly like the DVD recorder that ive used, a NEC AD 5170A. If you want i've info for you to use the diodes.


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## Mawaii (Jan 19, 2007)

I thought it's maybe also interesting for others, here a copy from a post that i've put on another laser forum:

I'm working on my second DVD laser diode. I took it from a brand new NEC AD 5170A recorder. It's my second one because i think i was a little rough with the first one :roll: 
It's easy to take out the optical unit without violence: open the box, just remove some screws and take it from the 2 metal rods. Inside the optical unit you will find 2 laser diodes, the infrared one for CD's, and the red one for DVD's. Carefull remove the glue with a small screwdriver, and peel away the plastic that surrounds the laser housing with a small nose plier. 






DVD diode:






Now it's time to find out how to connect it. There are three legs on the diode, the 2 legs that are both connected to each other (or at least it looks like) is negative, the other one is positive. 
It's not a bad idea to make a drawing of it :wink: 






It take's some soldering skills to remove the little circuit board that connect's the laser's legs.
When the legs are clean it's time to solder the wires. I used wire from an old CAT 5 ethernet cable, which is perfect to do the job. Presolder the wire and put it against the leg till it melt's against it. So you don't have to add any solder and heat, the diode likes that..

Now you can lite it up. I took 2 rechargeable cells (1,2 V/AAA/ Ni-MH) in series. Since i know that it's not a good idea to just hook it up without a resistor, to avoid to much current, i took some resistors and a pot meter, combined with a multimeter. 

4 * 3,9 ohm resistors in series, in series with a 290 ohm potmeter gives me a max current of 150 mA, that will be safe on a 18* DVD laser diode.
Now with everything connected, i can slowly increase the current. First it glows faint, like a led (spontaneous emission), but at 60 mA it start's to become much brighter. This point is the lasing threshold (stimulated emission). I slowly increase the current till max. (The multimeter says 135 mA at that point). 
A bright red glow lites up my room 8) 
I've put a little movie on You Tube where it pops a baloon.

click

On the DVD diode there's a little square shaped window. on my first DVD diode i took it off, because i thougt it had no use (for me). When i took it off i saw there was no glass or something to shield the tiny little "laser grain" from the dirty outside world. I think that it's what killed it after a day. 






Later i found out that the little window seperates the beam of light into 3 apart beams (profiler?).
Because the diode fit's tight in it's housing i didn't take it out, i don't want to break another one and i leave the 'window' on the cavity.
My next step is to add some extra cooling and a collimating lens, and put it in a nice box.


I also tried the IR diode, it works great as well, but i don't have plans with it (because of safety and so forth). 






Lasing threshold of that one is 40 mA. It was easy to find that out with my Apple iSight cam.
At 130 mA it burns through black plastic, and at 150mA (on 2 1,5 volt IKEA Alkalines), it stings your skin in seconds. I let it on for minutes and it didn't became very warm. Maybe it's possible to use it with an even higher current, but because it's invisible and not as 'safe' as the visible red diode, i don't have use for it yet.

update:

Here is a little (but boring) video from the infrared CD diode. At 160mA i was able to light a match in 1 or 2 seconds, with a little collimating lens. I sacrificed it for the laser hobbyists community and turn the current higher, it dies after a few minutes on 190 ma so stay at about 160 ma if you have this diode too.

movie

The red laser diode works perfectly well, ive put it in a metal frame that i've made from scratch, with a collimating lens. Running on a 3.7 v Li-ion Olympus camera battery, in series a silicium diode to lower the voltage to 3 volts, and that in series with a potmeter and 4 * 3.9 ohm resistors in parallel.


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## liveforphysics (Jan 19, 2007)

: Double Post : Damn server lag!


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## liveforphysics (Jan 19, 2007)

Thanks for the exellent info Mawii! This drive was a Liteon brand 18x DVD burner. I agree that it is likely a re-label of the same drive that you used. I would love to have the spec sheets for the laser diode if you have them. Thanks.


Later on yesterday I lit the diodes and did indeed find the one that I guessed to be the DVD module to be the DVD module. I discovered polarity from looking into the packageing and observing which pins had little hair wires going to the respective places. This also confirmed that the output monitering pin is not connected to anything. Well, from a totally divergent fairly random beam being underdriven, I was able to burn the ink off paper at a very rapid rate, like +1"/second. If I paused anywhere on the paper it imeadiately burned clear through leaving a jagged edge with lots of ash. Just for giggles I cut a heart out in paper with the laser and gave it to my girlfriend before work this morning .

I'm now just waiting for those Axiz laser modules with glass optics and variable lens focus points to arive to turn this fan of light into a tight beam of light. 

I don't know if my order at Roithner for the EU-38 power supply boards has been processed or not, as I haven't heard anything back from them, but I am pretty excited to turn this into a keychain sized portable laser module.


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## liveforphysics (Jan 19, 2007)

Mawii- Can you elaborate on what this 'profiler' optic does? You said it splits the beam into 3 parts, I am ignorant of the purpose and methods to do this.

Reguarding extra cooling, I am thinking about taking a syringe filled with some non-electrical conductive but exellent heat conducting epoxy. Something like this.

http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

Assumeing it was very carefully injected into the open laser diode module, can anyone see any reason why this would cause any problems? From a thermodynamic standpoint it should do wonders for lowering the deltaT between the case/packageing and the tiny parts that actually need to stay cool. Obviously care would be taken to ensure no epoxy approached the light emitting portions of the diode.

Thoughts?


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## Conrad_Turbo (Jan 19, 2007)

So at 40ma the IR diode was content putting out a decent IR beam? Does it get warm? Very cool post! Keep the info coming!


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## liveforphysics (Jan 19, 2007)

Well, I tested my IR diode for the first time. At 2.8v it gets warm after about 10seconds. The output was not able to even burn black ink off paper. The red diode smokes the ink off the paper, then procedes to burn through the paper in roughly a second or two. I'm not impressed with the IR diode, I have no idea what its beam pattern looks like, and it does have a lens afixed to it. It must appearently have some power, as the drive was able to burn CDs at a high speed. If anybody wants me to send it to them, just PM me an address and its yours.


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## Mawaii (Jan 19, 2007)

Conrad_Turbo said:


> So at 40ma the IR diode was content putting out a decent IR beam? Does it get warm? Very cool post! Keep the info coming!



40 ma is the lasing treshold, the point where it's start to being a laser. The output there is very low. But at 160 ma it burns a black match almost instantly (very narrow collimated beam). I was watching the proces with one eye at my iMac screen, as i pointed my iSight cam at it.. In the smoke i saw a nice bright beam there. With the naked eye only a deep red point. The diode didn't get very warm then.. But at 190 ma i killed it...


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## Mawaii (Jan 19, 2007)

liveforphysics said:


> Well, I tested my IR diode for the first time. At 2.8v it gets warm after about 10seconds. The output was not able to even burn black ink off paper. The red diode smokes the ink off the paper, then procedes to burn through the paper in roughly a second or two. I'm not impressed with the IR diode, I have no idea what its beam pattern looks like, and it does have a lens afixed to it. It must appearently have some power, as the drive was able to burn CDs at a high speed. If anybody wants me to send it to them, just PM me an address and its yours.



Strange.. Mine had a little focussing lens on it (see my black & white picture), and was strong. Did you measeru the current, and do you use any kind of resistance? Maybe you've already blow it..


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## Mawaii (Jan 19, 2007)

liveforphysics said:


> Mawii- Can you elaborate on what this 'profiler' optic does? You said it splits the beam into 3 parts, I am ignorant of the purpose and methods to do this.
> 
> Reguarding extra cooling, I am thinking about taking a syringe filled with some non-electrical conductive but exellent heat conducting epoxy. Something like this.
> 
> ...



I've made a construction with brass and copper, and put a collimating lens in front on it with the help of Dr. Ding's "Captain Fix" (2 component surfboard repair). It worked fine. But today i think i killed it, a wire from the switch touched the frame and then the whole thing dims. It still lases, but very weak.. So be carefull not to short circuit it, put resistance direct at the battery.. Oh, i also removed the beam splitter this time.


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## Mawaii (Jan 19, 2007)

liveforphysics said:


> Mawii- Can you elaborate on what this 'profiler' optic does? You said it splits the beam into 3 parts, I am ignorant of the purpose and methods to do this.
> 
> Reguarding extra cooling, I am thinking about taking a syringe filled with some non-electrical conductive but exellent heat conducting epoxy. Something like this.
> 
> ...



I've made a construction with brass and copper, and put a collimating lens in front on it with the help of Dr. Ding's "Captain Fix" (2 component surfboard repair). It worked fine. But today i think i killed it, a wire from the switch touched the frame and then the whole thing dims. It still lases, but very weak.. So be carefull not to short circuit it, put resistance direct at the battery.. Oh, i also removed the beam splitter this time.

Sorry for the bad quality of the picture, my photo camera is broken..


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## SenKat (Jan 22, 2007)

Here's a pic of my finished product - the dvd - burning beastie !






a little out of focus


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## 532nm (Jan 22, 2007)

Has anyone played with the DVD burners that also have the ability to etch titles on the DVD disc? Does that just re-use the same laser that burns the data?


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