What the Heck is This? (12 Pin Diode)

I had a burner in an old computer and took it apart hoping that I would find something inside that was half-way recognizable. Oh boy, was I wrong. I have no idea what this is.

The sled is from a Philips DVD/RW 2000 Series. I believe it is a DVD/CDRW combo drive, meaning I don't think this thing could ever burn DVDs. It's pretty old school. I actually upgraded a Windows ME machine with it back in the day.

SO! Without further adieu, I give you the 12 pin diode of doom!

The sled looked like this:




Here's the pins with the diode still in the heatsink.




Here's the front. The glass has a blueish tint to it, and it a little chunk that's just glued onto the front of the can. I haven't removed it yet. Don't know if I should.




Here's a side shot. You can see the numbers printed on the side and the little piece of glass glued to the top. Yeah, it's got the corner chipped off.




Other than that, I pulled out a a couple of rare earth magnets, a beamsplitter, and a right angle prism from the sled.

Anyone ever seen one of these before?

I would guess that there's either actually two diodes in there producing different frequencies, IR for CD's and visible red for DVD, or that there's a complicated photodiode/photoresistor feedback sensor in there that gets used for a control loop to regulate the output.

Or, since each diode would only really need two pins, perhaps three if they needed different case neutral/grounds for some reason, it's possibly all of the above, IR, red, and feedback sensors.

I was thinking along the same lines as AJ DUAL, so I did a little digging and found this pdf.

It's not the same exact part that you have, but I'm betting it's very similar. Notice that the laser output is only 300μW absolute Max. rating, and only 180μW typical at 795nm. I don't know if this is sufficient for reading at 16x speeds, or if it is only intended as a tracking/focus control sensor.

Also they call it a "hologram unit". I think it has an HOE (holographic optical element) molded into the front of the output window, possibly for beam shaping.


Anyway, it's an interesting piece either way.


-mega

I would break the thing apart in my opinion.

Doesn't look usable in any host type thing.

Nice find, but I don't think that is what it is. I have pulled several HUL's from old CD burners. They are all epoxy bases, SMD formfactor (only about 1/8thx1/4 inch), and the top lense is plastic. I also have a LD(?) similar to the OP, but it is a round (9mm) can, not oblong and has a 1/4 inch glass(?) cube glued on the top of the can. Can't remember where I got it exactly (think it came out of a Pacific Audio CD RW, maybe 8x). I'd love to find out what it is and see a datasheet....

i also pulled a diode smilar but in the 9mm can out of a pioneer early dvd writer. which i sent off to a member to have a look at.

it's a laser diode
some guys on the comments of this instructable (kipkay's hack a flashlight ) have extracted these things also and some had a breakthrough and powered one of those

see the comments here:
Continue extraction...

EDIT: don't bother about the comments see this thread - look down to post #5 -here is your answer i think (5minutes search)

http://laserpointerforums.com/f50/rectangular-12-pin-cans-36501.html

EDIT2: here is some tutorial to build one of these into a module and focus it

http://elabz.com/laser-diode-housing-from-hardware-store-parts/

Oh wow, interesting. Thanks! :beer:

I Just gutted a cd burner that had one of these diodes in it and under a microscope it appears t have 3 emitters in it ???? Whats interesting is the glass squared had a circle in the middle that acts as a diffraction grating and its broken into 3 sections.
Just thought I would share

joniy90st said:

I would break the thing apart in my opinion.

Doesn't look usable in any host type thing.

Click to expand...

Very nice 1st post :san: Welcome to the forum.

glass square is a diffraction lens. light on the way back gets diffracted off axis to the sensor. The laser diode is the chip that is mounted on the post. I think that glass optic is the most interesting part of these diodes. The circle is split into quadrants for some reason, too, and if I had better eyes, I might be able to make out the letters or numbers inside the glass.