Hello and Diode ID...

[falchionsmight]

I've been lurking for a few days, I just got a cheap green pointer, and caught the bug... I've got 3 lasers in the mail from DX...and I've only had the green one a week. I'm a Photographer, and my obsession has been with light, lasers are kinda like a dream come true for me.

On a different note, I've got some questions I'd like to ask, and any help would be greatly appreciated. I gutted a CD ROM drive, and I'm betting it has a IR diode in it... I found what has to be the diode, but it's very, very different from the diode cans that I've seen discussed on this forum, so anyone who might recognize this diode, and could help me find which contacts I should attach wires or a driver board to, it would be very helpful. Hopefully I can attach a picture...

Well, I just wanted to say Hi, and see if anyone recognized this diode-chip thing....

Falchionsmight

 

[falchionsmight]

Re: Hello

Here's the back side of the chip

 

[falchionsmight]

I found that the diode is indeed IR, and I found the pins on the ribbon cable, but not the diode, it should be a pretty simple matter to just trace the path to the diode, and go from there. So I answered my own question , it's all good though. This place is so COOL, I can't wait to build my own laser

 

[SenKat]

I was not ignoring the post - I was hoping someone would be able to answer your question, as I was at a loss ! Taht is by far the oddest IR diode - or diode PERIOD I think I have ever seen ! Put up some pics of that once you figure out how to power it, and cool it - be careful, heat is the enemy ! DAMNED nice pics, too - I am so very jealous, as I cannot for the life of me get the hang of the MACRO function on my camera - I have never been able to get even remotely that good of a closeup ! GREAT WORK !

 

[Tallaxo]

That is a strange looking diode, never seen one like that before

Jase

 

[falchionsmight]

SenKat, As for the Macro on my camera, I bought that camera specifically for the Macro. I've always loved Macro Shots, and when I was looking for a camera to buy (after I'd saved up enough money from my photography job) I looked at the Pentax Optio W20, and found out that not only was it waterproof, it had a focus distance of .4 inches. I though that would work well for Macros ;D I have the Optio W30 now, since I lost the W20. It's a better camera though.

I'll try to get some more macros of it up for you guys to see. And once I trace the paths, I'll be sure to label what I think is the cathode and anode on the chip. I thought it was a very odd diode as well, that's why I posted pictures of it, hoping someone might know something about it, but it's kinda nice to not be the only one at a loss with the thing. I have another CD ROM drive that needs to be taken apart, if it has the same diode in it, I'd be willing to send it to anyone who'd like to play with it, or I could sell it to someone if they wanted to keep it. I'll take some more macros of it, and I'll probably post them in the multimedia, or experiments section.

 

[pseudonomen137]

Hey falchionsmight. Sorry for the criticism, but I assure you its purely constructive criticism, especially if you're interested in macro photography (I too have bought cameras strictly for macro): I'm not sure if your camera gives this manual control, but if possible you should stop down the aperture as much as you can and stick it on a tripod if you're not doing so all ready. It'll give you a much longer shutter speed, hence the need for the tripod, but it'll let you get much more of the image in focus instead of just a small patch in the center. Good luck!

 

[falchionsmight]

Thanks for the help Pseudo, Mine really won't let me stop down too much, and I was doing those shots hand held in room lighting, at night. The second one was terribly out of focus. You're right about the f-stops though, lower would give me better DOF, and I've got an SLR that I could use on important macro stuff. I guess I don't have enough posts to post links, so I'll try to do the spaces thing, if anyone would like to see my laser pics on my website.

www.mattcoulter.net


I might try to take a macro of the diode putting out some IR sometime soon. Thanks again

***EDIT fixed link***

 

[falchionsmight]

Thanks for making the link work SenKat. I took some pics of the IR diode putting out some IR. Forgive the limited quality, it's on a modded webcam, but at least you can see the IR coming out of the thing. I used a multi-meter's diode mode to test this, and I figured everyone would want to see it putting out the IR.

 

[Daedal]

I have a feeling that tells me this is more than just a diode... DUH! Well... my speculation via pictures only is that this thing is a diode + photodiode. Although, I wouldn't know why the photodiode would have leads soldered to the front like a diode. It seems to me like it could be another diode of some sort. The leads soldered to the front sure make it look like it's a second laser diode by itself... Seems much like a laser dye kind of connection. Either way, try and see if you can find the photodiode elsewhere, and if not, that's probably it right.

GL;
DDL

 

[Tallaxo]

Great site you have there Fal, and some really nice work.

Jase

 

[falchionsmight]

Daedal, I'd look for more things on the chip if I knew what I was looking for, or how to look for it. The best I can do now is poke the pins, or solder points with a multi-meter (in diode testing mode of course). I don't know what would happen if I hit the photodiode, I haven't really worked with any, nor do I know anything about how they work. I understand diodes, or at least, partly do, but photodiodes are a mystery to me.

Thanks Tallaxo. I'm going to try to upload a good quality laser video soon. My proudest pictures are the one of my foot, with the faces on it, my dog as a bee, and the one I call Id, Ego, and Super Ego. I'll be sure to add some more laser pictures with my next update.

 

[Greenie]

I pulled and old cd drive apart and found the diode to be a little black chip. Looks like the center of your pic.
Also all the leads seem to end up on that chip.

Here is what I think is going on. I am most likely wrong

 

[falchionsmight]

You're probably right Greenie, That makes the most sense, because the IR Light is coming off the reflective surface, and then contacts go to the LD. Maybe there is a PhotoDiode behind the reflector, and it might be a beam splitter. Since this is from a CD ROM drive I don't see this diode being able to burn anything, or anything like that at all, I'm mostly looking at it as practice for building a DVD burner laser (but it's starting to look like this IR pointer would be more work than a DVD burner laser ). Thanks for the help, I hadn't looked at it that way, and that makes everything make a lot more sense!

 

[Greenie]

No prob, just wanted to add my thoughts on it.