Red vs. green

[Daedal]

Can someone please enlighten me as to why the red lasers (older technology) and the red laser diodes are in the range of 3-4 times the price of a green laser module?

Other than the fact that green uses an IR, I see no reason as to why red should be that expensive! I mean, I have contacted about 20+ companies and have yet to get a sensible price quote! If I can buy a fully assembled, tested, and very technical DVD burner for $30 shipped, why can't I buy an equivalent diode for less than 10 times the price?!

Any enlightenment would be greatly appreciated. Thank you;
DDL

 

[Ashton]

Look at the MW rating. Reds are DIRT CHEEP compared to greens! The ratio is almost 2:1 cost for equivolent mw!

And the reason is supply and demand. How many DVD-burners are needed? how many lasers? DVD burners are dropping because tehy are being sold insuch numbers. LAsers, as a whole, are not (excluding pointers)

I do agree, it owuld seem the technology invovled in a DVD-RW is far above that in a high-pwoered laser, and the laser for 70-240mw (dep on drive) shouldn't cost more than 2x what the drive does... but, such is supply and demand! This is why so many of us on here are building our own lasers from DVD-RW diodes isntead of buying them preassembled. hell, I'm looking at buying 5 or more 230mw DVD diodes and combining them into a single beam! a 1W laser for ~$300! (and that's a high-end esitmate!)

 

[SenKat]

Those are high hopes - but it IS possible ! I would love to see the finished product - I'll even bid on it if you decide to slap that sucker for raffle, or auction !

Ashton is right - mostly (You know I had to !) You CAN buy the red diodes at prices that are less than the DVD burners - but the problem is finding someone with a large enough quantity ! I am not sure of the exact nimber of diodes Dr Lava bought when he did his GB - but when I did mine, I was able to get 30 diodes shipped in for less than $20.00 each shipped out to new owners. That included the cost of the diodes, the HUGE shipping fee from Denmark, and then me sending them out to all the folks that bought them. That is not bad - I am sure that Dr Lava got a much better deal, with a larger quantity. I am looking ALWAYS looking for more diodes to mess with - if anyone finds a reputable source, I;ll either jump in on the Group Buy, or organize it - I want more !

 

[Daedal]

I definately want more. I'm in for 10 of them, even at $20 a pop. I've gone through so many DVD-burners it's not even funny!

--DDL

 

[VaThInK]

I definately want more. I'm in for 10 of them, even at $20 a pop. I've gone through so many DVD-burners it's not even funny!

--DDL

What kind of issues were you having with laser diodes in DVD-burners? I've salvaged 9 optical drives in total and all of them is working fine and dandy. Except when I was trying to find the maximum limit of current the diode can chew, which results in 5 very exotic red LED. In the end, I managed to push the diode at 750mA with good external cooling and at 400mA without. :goodjob: Now I just have to buy a meter to measure the power output that they put out.

Sorry, this is kind of off topic:
Anyway, is it just me or what? When I pushed the diode to its maximum. The wavelength seems like getting shorter (640~650nm region) as I'm seeing more orange/red colour and not just plain red. Anyone else had similar results?

Cheers.

 

[Daedal]

Not me, about the other colors, but I can tell you I didn't push the diodes that far at all! The diodes I have are mostly from Lite-On and Philips DVD burners... the idiots both use open package LD's. These things poop out, but they're HOT! They easily burn anything at just 100mA input! They have a very good effeciency, from what I've noticed. But give them a bit too much, or solder them more than once, and they literally break! The little wire connecting the pole to the dye just snaps. All the ones I worked on before just drop dead and they don't even do the cheap diode thing, they just get screwed. I am looking at possibly buying some closed package ones.

Also, the Philips DVD-burners are 100% identical to the Lite-On ones. From a choice of the two, just pick the cheaper one. I got several at around $30 a piece. Now I'm looking for some regular type diodes. Any suggestions?

Thanx;
DDL

 

[VaThInK]

Ah I see what you mean. Yeah, at first I hate the open can package as well and yes I accidentally pulled out the LD pin once, LOL (It wasn't funny then, but it is now). So I always use the diode when it's mounted in a housing such as the one you can get from AiXiZ on eBay. The good thing about his housing is that it doesn't only cover the diode itself but also has some room for driver board as well (In my case I put a resistor and tied a knot at the end so everything are locked inside). VERY NICE UNIT!

Here's a couple of pic:

Sorry about the crappy pics. They are taken with cell phone.

I salvaged my red diodes from Pioneer 112D and loving it. Very easy to take apart and the cheapest in AUS. The IR diode on the other hand is quite a b*tch to take apart.

I can't help you with the supplier of close can red diodes though. I'm interested my self if they're very cheap! Let say, cheaper than a DVD burner. Otherwise, I can't justify the extra cost. :thumbsdow

Cheers.

 

[SenKat]

Well - all I can say is - google the diodes - find a good supplier, and let the rest of us know !!!

 

[Kenom]

Has anyone pulled apart a sony dvd+r? I pulled apart my old plextor and it netted me a fairly nice LD normal little bugger too not a open one. Never even seen an open LD. I would figure that since sony is actually a manufacturer of LD's that the LD in a sony dvd rw would rock!

 

[SenKat]

I am actually surprised at the number of open die diodes that are being found in Lite-on drives - I have always bought ite-on, and never had an issue with an open die before.....My first diode project was a lite on drive, and was not an open die diode, so I am confused !

 

[VaThInK]

Has anyone pulled apart a sony dvd+r? I pulled apart my old plextor and it netted me a fairly nice LD normal little bugger too not a open one. Never even seen an open LD. I would figure that since sony is actually a manufacturer of LD's that the LD in a sony dvd rw would rock!

I've opened old 16x Sony, Samsung, Pioneer and Liteon DVD burners and they're all using open diode type, which makes me believe that all of 16x DVD burners use the same open diode type. I have also heard that 20x liteon DVD burner uses this very same diode as well.

Never seen a closed LD on DVD burners yet, except the IR LD.

 

[Kenom]

PLextor 16X had a normal diode in it. Might explain why i'm only gettng about 120mw from it. that or it's just cause the drive was dead to begin with.

Saw the stupidest thing on Smallville today. Season finale, episode 22 season 6. Lex and his bunch of baddies bust into a small hut in quebec and the phantom flies off through the ceiling. Lex's trusted henchmen has a Green laser of unknown make that he's holding shining it through the hole in the ceiling that phantom has excited out of. What would be the purpose of shining just a pointer out a hole in the roof? Everyone else had a red laser sight on thier guns but this guy just had a single pointer. STUPID. cheap special effects I suppose.

 

[ScarabDrowner]

I got a cheap NexxTech 20x at Circuit City ($55), with two diodes in it. one is so wedged into its heatsink I can't tell if it's open or closed, the other is in a fairly massive heatsink, and was thermal-epoxied to the chassis, but it's open... I can see the two leads from the back inside the diode. but i have no idea which diode is what.

 

[Kenom]

I would bargain to say that the one pictured above is the red on. the easiest way to tell is to test the thing with a diode check on a multimeter. The current sent through it in the check mode is enough to get it to light up but NOT LASE. was taught this nice little trick by someone else on this forum. if it's red then problem solved. If you cannot see anything then it's probably the IR diode.

 

[SenKat]

Kenom - excellent ! I would have the diode pointed at something dark colored to see the light, to avoid any danger to your eyes - also, in that pic below, the third leg of the diode could be the massive copper looking "plug" under the other two pins...which means that one is the one that is grounded to the case...most likely negative....

It's hard to tell form the pics, though....

 

[Kenom]

Can someone post a picture of the open style dvd LD's?? I would like to see one without having to go purchase a dvd burner to rip apart. I've got another Plextor here that has been screaming for my crowbar but it has been promised to SenKat. that and I know it's not a open style. i think?

 

[SenKat]

When I tear apart my dying light scribe Lite on - I actually hope it has a open LD in it, so I can take some pics of it....

 

[ScarabDrowner]

just checked... I don't see anything with the above pictured diode, when using the dmm to check it. I think it's IR. The other smaller diode, wedged into its heatsink (and which I just now accidentally broke off the positive lead) is the red one, I can see it glow slightly

 

[Kenom]

Bummer. that would have made one heck of a good red laser. and bummer to hear ya broke the red one. It's one of the hazards of doing this stuff ourselves. So now you have a high output IR diode that might make a good IR laser and a broken red one. MY condolences.... Plays taps on computer and takes of hairpiece for a final salute to one LD.

 

[Daedal]

just checked... I don't see anything with the above pictured diode, when using the dmm to check it. I think it's IR. The other smaller diode, wedged into its heatsink (and which I just now accidentally broke off the positive lead) is the red one, I can see it glow slightly

In the picture above you can clearly see that the pin on the left of the diode is the lasing pin and the ground is the heatsink. Look at the fine copperwire inside the diode. This is how I have been checking my diodes lately.

Can someone post a picture of the open style dvd LD's?? I would like to see one without having to go purchase a dvd burner to rip apart. I've got another Plextor here that has been screaming for my crowbar but it has been promised to SenKat. that and I know it's not a open style. i think?

The pictured diode up is the open one I was talking aout...

I pulled pins before, broke the copperwire inside, and I have burnt them from over power. All lead to the same effect: no more light out of the diode. The thing I was pointing out is that these diodes to not simply turn into an LED, they just poop out and die! Such a bummer.

I ordered an LG 20x, expecting it in sometime next week. I'll update once I get that in. Hopefully it's a closed package

Well - all I can say is - google the diodes - find a good supplier, and let the rest of us know !!!

Tried it, and I already said nothing I found was reasonable! The cheapest I got is in the thousands! This is true for all volume sales as well! I really hope someone can stumble on some LD's. I'd be in for 10 minimum. I did manage to get a hold of some ~60mW diode for about $3 a piece shipped

Thank you all for the input;
DDL