Looking for C-Mount 808nm

[MechEng3]

You will probably find that replacing the laser is cheaper.... figuring in the time it takes to install and dial everything back up to par...plus the cost of the diode. 532 is the cheapest going....unless you want to just for kicks. I guess it actually depends on the deal you get on a few diodes...there was a partial tray of 500mw diodes on flea-bay a few weeks ago pretty reasonable. I would be sure that the wavelength was +/- 3nm....some sell diodes with +/-10nm witch will work if they are temp tuned very close...but life can be much easier if they are close to spec at 808nm. Be sure they have a FAC installed.

[Lazerjock]

Now snoctony has some on eB
Piotr.K

Thanks! I ordered a 500mw from him. We'll see how it works.

Yea, MechEng I'm trying it just for kicks. If it works well I have several I will rework. This is more of an experiment at this point. I can't help myself, if it's broke I have to try to fix it (and make it better).

It will take a couple weeks to get it from China, I'll post the results.

Lazerjock

[Lazerjock]

Well, I got my 500mw 808nm C-mount pump diode yesterday.

The first thing I noticed was the packaging. It was well packed in a small box with bubble wrap around an ESD bag holding the diode. I was concerned about the facet since it could come in contact with the insdie of the ESD bag.

I would have expected it to be screwed down to the inside of an ESD box to prevent sliding around.

Once unpacked I simply unscreded the damaged diode from the heatsink and screwed the new on in its place then solder 1 connection. That's it!

I reset to current on my driver and powered it up.

Wa La! We have a green laser again.
It was easier than replacing a BluRay or LOC red.

I'm not going to say all 532's are going to be this easy, but the cheep 80-100 mw 532's without a TEC are a cake walk.

Lazerjock

[hobbybob]

Hi LazerJock,

Cool to hear you were able to fix it. I still have 150mW green i fixed at UKLEM last year.
But after playing with it i wrecked it (again) i think, so will have to fix that one again.
After i replaced the diode 212mW came out (instead of the original 154mW) ;-)

Did you make some photos of the rescue operation ? I always find those very helpful and they might be for others to take the plunge and try themselves !

[Lazerjock]

I'll take some pictures and post them. I knew someone would ask. Usually it's Allthatwhichis.

[allthatwhichis]

I'll take some pictures and post them. I knew someone would ask. Usually it's Allthatwhichis.

...............

[Lazerjock]

Here are some pictures of the diode replacement.

Make sure you do this in a clean place. I can do this at work in a clean room and flow booth. The fewer particles that get into the laser cavity the better.

To gain access to the diode simply remove the two small screws form the heat sink/diode mount.
Lift the heat sink/diode mount out of the laser assembly.
Note there is heat sink paste around the edge of the heat sink/diode mount. It's there to make a good thermal bond between the heat sink/diode mount the housing. Try not to touch this.
Once you have the heat sink/diode mount out of the housing you will be able to see the diode.
You will have to de-solder the positive lead which is simply a strip of copper.
The diode is held in place with 1 screw. This also acts as the negative contact.
The new diode comes in a ESD bag. Before removing the new diode make sure you are grounded to discharge any static build up.
The diode has a very tiny facet that the light emits from. If you look close you will see very thin wires coming off the copper strip going to the facet. It is very important not to touch this with anything.
Place the new diode on the heat sink/diode mount, center it and replace the screw.
Solder the copper strip to the positive lead.
Place the heat sink/diode mount back in the housing and screw down.
That's it.

I hope this helps.
Lazerjock

[ElektroFreak]

I've got a bunch of those modules at home, many of which I've repaired this way. They're a breeze, but the output is a bit unstable since they're passively cooled. If you were to use a 1W pump diode running at about 750mW you get roughly 120-150mW out. If you were to do this, I'd recommend setting the whole module on a TEC since it will get a bit warm after 15 minutes or so.

[Lazerjock]

I've got a bunch of those modules at home, many of which I've repaired this way. They're a breeze, but the output is a bit unstable since they're passively cooled. If you were to use a 1W pump diode running at about 750mW you get roughly 120-150mW out. If you were to do this, I'd recommend setting the whole module on a TEC since it will get a bit warm after 15 minutes or so.

Nice! I'll have to try that. Are you sure the optics can handle that much power without burning?
The lasers I'm repairing were originally rated at 50mw but put out 80-100mw. I figure they were already being pushed to the limit, but I really don't know.

[ElektroFreak]

All I can say about the optics is that I haven't had anything burn up on me except the original diodes so far. You never know what might happen as the hours build up, but for a ~$70 greenie I wouldn't worry too much. It's still very good bang for your buck. I've actually been quite surprised by how much pump power the coatings on these small hybrid crystals will handle.. One thing is that if you go too high, you'll exceed the mode volume of the crystal and the beam quality (which, surprisingly, is typically EXTREMELY good with these modules) will suffer, with higher-order modes being generated.