Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Do Diodes Extracted From CD/DVD Drives Vary?

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
Ok so, I got a question.

Obviously you can extract red diodes from various CD/DVD RW drives.

Do these diodes vary greatly depending on what drive you harvest them from whether in power, wavelength, efficiency, lifetime..etc?
 



Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,837
Points
113
The power is proportional to the write speed. That is to say a 16x drive will typically have a higher power diode than a 8x drive. The other parameters will be about the same. Some diode cases are not easily re-purposed because they are a nonstandard form factor.
 

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
The power is proportional to the write speed. That is to say a 16x drive will typically have a higher power diode than a 8x drive. The other parameters will be about the same. Some diode cases are not easily re-purposed because they are a nonstandard form factor.
That sounds good!

Is 16X the highest power drive to harvest from?

And by non-standard form factor, you mean some drives aren't harvestable as the red diode is not a 3.8mm or 5.6mm?
 

hakzaw1

Well-known member
Joined
Apr 2, 2009
Messages
10,461
Points
113
I dont think very many are still doing that.

AND new highpower 'reds' (3.8, 5.6 & 9mm )are less expensive now, and the 635 and 638 nm make a great HH or lab laser.
some say it takes >1W of 660nm to match iirc 250mW of 640nm-vid at show forum.



Teensy red module $4.15
I looks to the about the size a grain of rice (cooked) lol size as the mini mag light bulbs. has plug-in 'legs'.. myb made to plug into PCB..
650nm 3mW Mini 2x12mm 3.2VDC Laser Module. Worlds smallest, built in ACC 10mA draw at 3.2VD
they are not cheap.
bbl
hak
 
Last edited:

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
Ok, so I tried to do some digging on Google.

All I'm seeing is deep explanations of the engineering and technology being optical drives and not what speeds are actually available.

To get a red diode IIRC it needs to a CD or DVD drive and be RW right? I saw 24X, 48X, and heard of 52X. Does anyone happen to know basically what is the highest power diode that can be extracted, i.e. write speed?

Cause I'm getting confused between the different "CD" "DVD" "R" "RW" variables and corresponding write speeds meaning different things.
 

aaronnoraa

Active member
Joined
Jun 20, 2015
Messages
180
Points
43
To get a red diode IIRC it needs to a CD or DVD drive and be RW right?

It must be a DVD drive to get a red diode. Well, a CD drive will give you a red diode, it's just a band of red that won't be visible.

If you want a more powerful diode than ~1mw, yes, it must be a RW drive.

This means that you will (typically) have 2 diodes on the optical sled (except for stupid sleds that have a multi-wavelength, dual diode.. diode.. that has both 655nm DVD and 785nm or whatever [who cares] for CD) and will need to figure out which one is which. Typically, the diode itself or the molded heatsink will appear "beefier" on the DVD diode. Otherwise you just need to hook them up with a low current and check.

Just because you don't see anything doesn't mean that you're not powering the IR CD diode. Hopefully it's not collimated and you're not staring right at it.

These can be tested while they're still in the sled. Just rip off the final lens off the top of of the sled (the one you see if you look at the top of it, the bouncy one on the voice coil focusing mechanism), throw it away because it's useless, then put your leads on top of the solder joints connecting the ribbon that feeds the diode. Laser stuff will come out of the hole that was left under where you brutally ripped off the useless lens.

You can actually keep the diode in the sled and get a usable beam from it without needing to remount the diode in a module with a lens. You'll notice if you tested the diode in the sled that what comes out of the laser hole is a bunch of beams with one main bright beam in the center. That's because an annoying diffraction grating is in the beampath, just like the diffraction gratings that come with cheap laserpointers but instead of making a thumbs up figure or the word "slut" or whatever they do with those things, it just makes a bunch of stupid dim beams on each side of the main beam.

Your mission is to rip that diffraction grating out and throw it in the trash. For this, razor blades are your friend (also for cutting the adhesive that holds down the lenses and prisms, if you want to harvest them). It's a thin glass wafer usually mounted right on the output of the heatsink assembly holding the diode. It can be mistaken for a can window. Don't be fooled by it's lies. Now you have a single beam using the collimating lens that's mounted somewhere in the beampath.


Yay.

I saw 24X, 48X, and heard of 52X. Does anyone happen to know basically what is the highest power diode that can be extracted, i.e. write speed?

Since it's going to be DVD specs you're interested in you can forget about 48x and 52x since those numbers are for CD read/write performance and you don't care whatsoever about that.

It's going to be the DVD write/rewrite numbers that matter. So you'll be looking at 24X (I think that was the fastest rewrite speed produced for DVD/RW) or 16X (still quite powerful) or 8X (I think fastest on *laptop* DVD/RW drives, some have diodes that surprisingly can be driven to near 16/24x outputs likely with greatly reduced life, also often 3.8mm form factor open can diodes) or 4X (if it sucks).

300mw+ on 16X/24X drives if fed with 300-350ma of current

So it's 655nm and sure, that sucks, but that beam is tight like a tiger so the spot can actually look bright as hell.


Slower drive? Use less current.

Does it burn?


Yes, eventually.
 
Last edited:

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
It must be a DVD drive to get a red diode. Well, a CD drive will give you a red diode, it's just a band of red that won't be visible.

If you want a more powerful diode than ~1mw, yes, it must be a RW drive.

This means that you will (typically) have 2 diodes on the optical sled (except for stupid sleds that have a multi-wavelength, dual diode.. diode.. that has both 655nm DVD and 785nm or whatever [who cares] for CD) and will need to figure out which one is which. Typically, the diode itself or the molded heatsink will appear "beefier" on the DVD diode. Otherwise you just need to hook them up with a low current and check.

Just because you don't see anything doesn't mean that you're not powering the IR CD diode. Hopefully it's not collimated and you're not staring right at it.

These can be tested while they're still in the sled. Just rip off the final lens off the top of of the sled (the one you see if you look at the top of it, the bouncy one on the voice coil focusing mechanism), throw it away because it's useless, then put your leads on top of the solder joints connecting the ribbon that feeds the diode. Laser stuff will come out of the hole that was left under where you brutally ripped of the useless lens.

You can actually keep the diode in the sled and get a usable beam from it without needing to remount the diode in a module with a lens. You'll notice if you tested the diode in the sled that what comes out of the laser hole is a bunch of beams with one main bright beam in the center. That's because an annoying diffraction grating is in the beampath, just like the diffraction gratings that come with cheap laserpointers but instead of making a thumbs up figure or the word "slut" or whatever they do with those things, it just makes a bunch of stupid dim beams on each side of the main beam.

Your mission is to rip that diffraction grating out and throw it in the trash. For this, razor blades are your friend (also for cutting the adhesive that holds down the lenses and prisms, if you want to harvest them). It's a thin glass wafer usually mounted right on the output of the heatsink assembly holding the diode. It can be mistaken for a can window. Don't be fooled by it's lies. Now you have a single beam using the collimating lens that's mounted somewhere in the beampath.


Yay.



Since it's going to be DVD specs you're interested in you can forget about 48x and 52x since those numbers are for CD read/write performance and you don't care whatsoever about that.

It's going to be the DVD write/rewrite numbers that matter. So you'll be looking at 24X (I think that was the fastest rewrite speed produced for DVD/RW) or 16X (still quite powerful) or 8X (I think fastest on *laptop* DVD/RW drives, some have diodes that surprisingly can be driven to near 16/24x outputs likely with greatly reduced life, also often 3.8mm form factor open can diodes) or 4X (if it sucks).

300mw+ on 16X/24X drives if fed with 300-350ma of current

So it's 655nm and sure, that sucks, but that beam is tight like a tiger so the spot can actually look bright as hell.


Slower drive? Use less current.

Does it burn?


Yes, eventually.
Wow, that's quite a colorful choice of words you have for me! Badum Tish!

So then 24X DVD RW is what I'm looking for right? (For the most powerful diode available in these)
 

aaronnoraa

Active member
Joined
Jun 20, 2015
Messages
180
Points
43
Wow, that's quite a colorful choice of words you have for me! Badum Tish!

So then 24X DVD RW is what I'm looking for right? (For the most powerful diode available in these)

Yes. Hopefully it doesn't have one of those flat, plastic 4 pin multi-diode diodes in it. If it does, swear a bunch, then power it up and be disappointed.

If you accidentally wire it reverse polarity and blow it you may have actually saved yourself net disappointment, you just won't know it.
 
Last edited:

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
Yes. Hopefully it doesn't have one of those flat, plastic 4 pin multi-diode diodes in it. If it does, swear a bunch, then power it up and be disappointed.

If you accidentally wire it reverse polarity and blow it you may have actually saved yourself net disappointment, you just won't know it.
Thanks I'll definitely look out for that.

Would you know how much maximum power a diode from that can push without sacrificing life?
 

aaronnoraa

Active member
Joined
Jun 20, 2015
Messages
180
Points
43
Thanks I'll definitely look out for that.

Would you know how much maximum power a diode from that can push without sacrificing life?

If you're asking what the rated output is for various rom sled diodes, I'm not sure if that information is easily obtainable since most of the diodes are difficult to identify, however some can be ID'd accurately.. such as the Mitsubishi open can diodes. A safe conservative bet would be that running and 16X or 24X harvested diode at 175ma should be within it's rated output and achieve full life.

Running the 16x/24x diodes at at 275ma should deliver a long life at reasonably high power, but most people I remember drove them at 325-375ma.

They're so cheap and plentiful that you might as well run them at 325 for a pointer, if it dies just pop another one in. Those drives can be found for free or a buck or two if you look around.

I ran a 3.8mm open can Mitsubishi diode out of an Apple branded 8x ROM drive from a white Macbook at 275ma and it lasted a couple of years, often running for 20 or 30 minutes at a time. Those may have been overrated diodes for the application they were serving, though.
 

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
If you're asking what the rated output is for various rom sled diodes, I'm not sure if that information is easily obtainable since most of the diodes are difficult to identify, however some can be ID'd accurately.. such as the Mitsubishi open can diodes. A safe conservative bet would be that running and 16X or 24X harvested diode at 175ma should be within it's rated output and achieve full life.

Running the 16x/24x diodes at at 275ma should deliver a long life at reasonably high power, but most people I remember drove them at 325-375ma.

They're so cheap and plentiful that you might as well run them at 325 for a pointer, if it dies just pop another one in. Those drives can be found for free or a buck or two if you look around.

I ran a 3.8mm open can Mitsubishi diode out of an Apple branded 8x ROM drive from a white Macbook at 275ma and it lasted a couple of years, often running for 20 or 30 minutes at a time. Those may have been overrated diodes for the application they were serving, though.
Thanks for the extra information on the current I can expect. I'll be building a DIY driver for the diode, so this is something I'll have to figure out.

But, the main thing I was wondering is how many mW can 24X diodes produce typically?
 

aaronnoraa

Active member
Joined
Jun 20, 2015
Messages
180
Points
43
Thanks for the extra information on the current I can expect. I'll be building a DIY driver for the diode, so this is something I'll have to figure out.

But, the main thing I was wondering is how many mW can 24X diodes produce typically?

Something like 350ish if you run them at 325ma. That may not sound like a lot, but you will probably be very surprised at how bright they appear due to how tight the beam is on those single mode diodes.
 

Snecho

Well-known member
Joined
Oct 2, 2019
Messages
838
Points
93
Something like 350ish if you run them at 325ma. That may not sound like a lot, but you will probably be very surprised at how bright they appear due to how tight the beam is on those single mode diodes.
Oh that's pretty cool. So running them at 300mW would be a good idea for a balance of high output and good life I would think. Nice to know they should be single mode diodes.

Thanks again for the valuable information.
 

hakzaw1

Well-known member
Joined
Apr 2, 2009
Messages
10,461
Points
113
You would not save much on reds by harvest-
a 650nm red is a only 1/4 the power (brightness) of a 640nm.

techhood sells nice ones with the correct driver.. go for 635 to 638 nm
the 640nm is very spendy..

just be sure you know a lot about Static and diodes-- myb the most common way to ruin a diode--AND always short ALL CAPS.. good luck..
hak
 




Top