Red laser on a chip with PD arrays - is there a housing for it?

[scriptster]

I'm harvesting a few HP SDVD8821H 8X DL DVD±RW laptop drives for parts (stepper and red laser). The stepper looks fine for my application but the red laser happens to be on a single chip with a photodiode array (side note: why aren't they all like that - the optics are so much simpler!). I haven't seen this type of sled before: both red and IR laser diodes are on a chip with a PD array, there isn't a single individual diode there.

The body looks like a can with parallel sides cut off (I'll try to include pictures below) and the biggest diameter is, sadly, 8.25mm - too small for a 9mm housing of which I have one. Honestly, I'm not too sure if the LD is perfectly centered on the chip although that would have been ideal and I hope it's true. I played around with it a little - the output is strong and I hope it would perform just as well as other, round, 5.6mm ones I have. But the weird body shape/size is a drag - I don't have any housing to put it in (and I need focusable lens with it, too).

So, the question is: has anyone seen a housing that would accommodate one of these and a focusable lens? Any pointer in the right direction or a link will be greatly appreciated. I have 5 of these and would really hate seeing those go to waste.

 

[GBD]

Probably not much help on my behalf, but I never seen and don't think there is a commertial housing for these diodes (aside from where they came from).

Its most likely you will need to machine a heatsink to fit it mate..

 

[benmwv]

I would just set it in a 9mm housing with thermal epoxy

 

[JLSE]

That is one odd looking LD. looks like a squished 5.6mm :thinking:

If you have access to a mill, shouldnt be
too hard to make a mount.

 

[scriptster]

That is one odd looking LD. looks like a squished 5.6mm :thinking:

If you have access to a mill, shouldnt be
too hard to make a mount.

It's more like a 9mm with sides filed off actually. When I looked at it I though a-ha, I'll sit this right into a 9mm housing! But then reality set in: it's mere 0.5mm too small. I might have tried to set it in 9mm with epoxy but the O-Like's 9mm housing I have is a hack job, definitely a step down in quality from their 5.6mm housings that I like very much. The recess where the diode would have to be pressed into has a rather rough bottom side and I can't seem to position the diode straight - it tries to wonder to the sides and wobble.

Anyways, yes, I wish I had a ready access to a lathe or/and a mill but I don't. Maybe it's just one more reason to buy a mini-lathe? I've been looking at one at Harbor Freight for years...

 

[Tech_Junkie]

I've seen these posted before. To me its not worth buying a lathe just to get it to fit a heat sink. The LPC diodes are about as high power as you can get, and cheap too. Makes better sense to go that route.

 

[JLSE]

To accommodate all the surface area youd need to mill it, or be really
good with a lathe and cutting off center...

You can try putting an old lens in the 9mm mount and just use it to 'square'
the LD's position and epoxy in place. OR drill out an aixiz module at the correct
size right through giving space for the wide can and then epoxy.

You need some sort of way to square its position to the lens, or you'll get
an odd beam..

Like TJ said, I wouldnt buy any heavy tools for this, but if you just
need an excuse to buy a lathe...

 

[scriptster]

The LPC diodes are about as high power as you can get, and cheap too. Makes better sense to go that route.

I guess, my thing is: I have a handful of these diodes for free and I'm looking for ways to put them to use. Also, they are in a sealed can which I like because some of the LPC diodes I see being sold are open cans and they are harder to work with.

 

[Tech_Junkie]

Hey man all the power to you. If you have the time, and money to play with, go for it by all means.

 

[scriptster]

To accommodate all the surface area youd need to mill it, or be really
good with a lathe and cutting off center...

Honestly, I'd be more concerned about cutting the thread needed for AixiZ lens, which is the only lens type I have handy. My lathe skills are now under some 30+ years of rust and in my head I still can't figure out how they cut this internal thread so close to the dead end (talking about O-Like housing, not AixiZ). Well, unless they are cutting it with a fancy tap. Anyone knows?

Like TJ said, I wouldnt buy any heavy tools for this, but if you just
need an excuse to buy a lathe...

That's exactly the point! I think one needs not only an excuse but also an additional incentive because a tool like a lathe would need some space and some training (=time off playing with lasers), too, in addition to the obvious costs. So, yes, this may be the last straw for me

Still, if the housing I'm looking for actually exists, I would prefer a professionally made solution, so I'm still looking for a housing for this weird diode even though I'm getting myself (mentally) prepared for the DIY route.
:thanks:

 

[lasersbee]

Yeah..... FREE LDs aren't really free when you need to
put out $$$$ for equipment to be able to use/mount them...:cryyy:

Jerry

 

[rhd]

Is the threading inside the BACK of an Aixiz module (where it screws into the main module) the same as the lens threading? I don't have one here to check.

It would be awesome if so, because you could drop the diode to the bottom of the aixiz back portion, with wires coming out the hole. Then thermal epoxy it snug, and use the threads to mount your lens.

Seeing as most of us have a ton of those back modules kicking around, it would be a good recycling effort.

ACTUALLY -

Someone with the tap/tool to make custom focus adapters could probably help out here. Even if the back portion of aixiz modules isn't threaded the same as a lens (and it probably isn't), what someone could do would be:

1) Cut 3 or 4mm off the end that is threaded
2) With the lens thread tap they normally use for custom focus knobs, put new lens threads into the housing.

And there - universal "housing" for odd shaped square diodes. Just solder the wires on, thread through the open back of the housing, drop the diode down to the bottom, thermal epoxy as straight as possible - poor mans aixiz housing that would work in standard heatsinks Recycling!

 

[scriptster]

Agreed, [almost] nothing is free upon closer scrutiny

Yeah..... FREE LDs aren't really free when you need to
put out $$$$ for equipment to be able to use/mount them...:cryyy:

Jerry

Well, indeed, as is the case with many other free things in life :cryyy:
However, these LDs appear to be a special case - [broken] laptop DVD-RWs are cheap and plentiful, looks like the easiest way for someone to get their hands on a (635nm?) laser diode. I'm surprised this issue hasn't come up before... Or has it?

 

[scriptster]

Is the threading inside the BACK of an Aixiz module (where it screws into the main module) the same as the lens threading? I don't have one here to check.

I do have one "classic" AixiZ housing (though not a big fan - use O-Like's instead whenever possible) and I think that what you call "main module" is actually just what's commonly called "hood" on a connector - just a protective cover. What you call "Aixiz module" would probably be called "diode host' - it's the part the diode is pressed into. I just didn't have a picture of it, disassembled, handy. Otherwise precise terms would not be necessary.

So, anyways, no, the threads are different. The lens assembly has what appears to be M9 thread. Not sure about the pitch, I think it's M9x0.5 or something like that - I don't have a good way of measuring these weird metric threads, the ones not used in common fasteners. The thread between the host and the hood appears to be M11 (again, not sure about the pitch)

It would be awesome if so, because you could drop the diode to the bottom of the aixiz back portion, with wires coming out the hole. Then thermal epoxy it snug, and use the threads to mount your lens.

Seeing as most of us have a ton of those back modules kicking around, it would be a good recycling effort.

I'm all for recycling, I really am - one of the reasons I got involved with these broken DVD-RW drives. But the size is way off- it would put the lens too far away from the diode. Also, the walls of the hood are not thick enough to cut internal M9 thread on it.

ACTUALLY -

Someone with the tap/tool to make custom focus adapters could probably help out here. Even if the back portion of aixiz modules isn't threaded the same as a lens (and it probably isn't), what someone could do would be:

1) Cut 3 or 4mm off the end that is threaded
2) With the lens thread tap they normally use for custom focus knobs, put new lens threads into the housing.

And there - universal "housing" for odd shaped square diodes. Just solder the wires on, thread through the open back of the housing, drop the diode down to the bottom, thermal epoxy as straight as possible - poor mans aixiz housing that would work in standard heatsinks Recycling!

it won't work with AixiZ hood, again, the walls are too thin to cut the needed internal M9 in them. However, the idea itself may be viable if one can find a brass [aluminum] tube with a proper internal diameter. Then it would need to be threaded on both ends with the M9. One end would receive the lens and the other - some sort of a thick washer with external M9 thread and a hole for the diode. Well, honestly, that last part is exactly what would have been done on a lathe easily.

In any case, this "poor mans aixiz housing" (you coined the phrase, you deal with AixiZ intellectual property people :crackup would only work with a 5.6mm diode and I've got an almost 9mm one (8.25mm to be exact). This is too close to the entire internal diameter of such tube - the washer would have to have paper-thin walls, i.e. won't work. But thanks for sharing the idea!

 

[qumefox]

Cutting the threads for m9x.5 lenses is no big deal at all or hard. Just use a bottoming tap...

I have a few of these diodes as well. IMHO they aren't worth messing with at this point in time. No stronger than LOC's (usually weaker, the ones i've tortured) and it takes a LOT of machining to make a usable mount for then..

like Jerry said, Free isn't really free when it's a PITA to do anything with the diodes.

And whoever mentioned turning down these diodes on a lathe.. that won't work either. The outermost pins are the ones that go to the die. Shave those off, and you have to figure out how to add new bonding wires to the die.

 

[scriptster]

trash==treasure ? free != no_cost

Cutting the threads for m9x.5 lenses is no big deal at all or hard. Just use a bottoming tap...

The sucker is not easy to find, at least not in the US. Most places sell just the taper, some would sell a plug but none seem to carry the bottoming tap. Anyone knows a source?

I have a few of these diodes as well. IMHO they aren't worth messing with at this point in time. No stronger than LOC's (usually weaker, the ones i've tortured) and it takes a LOT of machining to make a usable mount for then..

Not sure why you say lot of machining - you don't suggest I mill the hole in the exact shape of the diode, right? It would seat just fine in a circular ⌀6.45mm hole on a ⌀8.25 flange.

But the issue of weakness would be a show-stopper of course. I don't have an optical power meter yet, were you able to measure the output? Can you share current/output observed?

Thanks!