IR diode sources.

[mfo]

Well, I'm looking for an IR diode to build a pen with. I know IR is dangerous and blah blah blah but I want one to add to the collection. I'm looking for an IR diode that will fit inside of an aixiz module and will will put out around 250mW or so. Also, the further into the IR region the better. Anyone know of any sources besides DPSS lasers? I'm guessing CDRW diode?

 

[Eudaimonium]

CD diodes are about 780nm IIRC, so it does not qualify.
Also, it is 150 mW for long life at max.

There were measurements done by Bill, if you want them I will post them (Power / current for CD ones)

Also, what you need it 5.6 mm can diode, while most common ones (worth using) are 9mm can diodes, you can get like, 0.5 W from those.
You can also get 1 W 9mm cans, however it won't fit in pen-style host, since it will need about 1.2 A of current.

In any case, ask billg519 here for some IRs, that is his speciality area of spectrum, you can see his videos on youtube, with 1W & 2W ir lasers and everything.

 

[ElektroFreak]

I'm a fan of 808nm myself. This store on ebay sells LOTS of diodes and laser related stuff.. they are very reasonable, and snoctony is a very reliable seller. Something like this diode should work.. the TO-18 package is the same as 5.6mm.

With 808 there is still enough visibility that you can see the faint spot so aiming is fairly easy, and you can use the laser to pump crystals if you have any around..

 

[mfo]

I'm a fan of 808nm myself. This store on ebay sells LOTS of diodes and laser related stuff.. they are very reasonable, and snoctony is a very reliable seller. Something like this diode should work.. the TO-18 package is the same as 5.6mm.

With 808 there is still enough visibility that you can see the faint spot so aiming is fairly easy, and you can use the laser to pump crystals if you have any around..

Thanks a lot. I might even get the 980nm diode. I noticed it's 9.0mm though. Would that produce a fatter beam?

 

[ElektroFreak]

Thanks a lot. I might even get the 980nm diode. I noticed it's 9.0mm though. Would that produce a fatter beam?

If you feel like taking a chance on what you're getting, I have a few far IR 9mm diodes between 500mW and 2W that I'll sell for $25 plus shipping for the lot. I'm not at home right now, but I think there are at least 6.

Regarding the beam, all of these lasers are multimode, so yes, the beam will be fatter and quite difficult to collimate. They can be easily focused for burning, but collimating a beam is tough and requires several lenses of various types.

 

[mfo]

If you feel like taking a chance on what you're getting, I have a few far IR 9mm diodes between 500mW and 2W that I'll sell for $25 plus shipping for the lot. I'm not at home right now, but I think there are at least 6.

Regarding the beam, all of these lasers are multimode, so yes, the beam will be fatter and quite difficult to collimate. They can be easily focused for burning, but collimating a beam is tough and requires several lenses of various types.

Is that because of the diode or because of the wavelength?

 

[ElektroFreak]

Is that because of the diode or because of the wavelength?

Because of the diode. There are some common misconceptions about IR being "difficult to collimate". This is untrue. It isn't well-collimated by optics chosen for 532nm, which is the source of the misconception, but if you choose the right lens combination with focal lengths calculated for IR it collimates just as well as any other light.

 

[ElektroFreak]

Is that because of the diode or because of the wavelength?

Because of the diode. There are some common misconceptions about IR being "difficult to collimate". This is untrue. It isn't well-collimated by optics chosen for 532nm, which is the source of the misconception, but if you choose the right focal lengths for IR it collimates just as well as any other light. Of course, multimode lasers in general are incapable of being collimated as well as singlemode lasers, so that will be a factor.

 

[Eudaimonium]

They are somewhat more difficult to focus because of their beam shape,

a common beam from 5.6mm diode is nearly-round, oval a bit, because the emitting surface is (I'm guessing numbers) like, 10x 30 micrometers.

Now, to output a large amount of light, you need more surface, so in high power diodes there is like, 10 micrometers x 0.5 MILImeter, so the beam looks like a stripe and not circle.

There is a fast axiz and slow axiz divergence, you need cylindrical lens to squiese fast axis to aproximately the divergence of slow one. If you don't know what I mean (I ain't good at explaining things without drawings in which I suck), I will draw it out for you. Or at least try

 

[billg519]

I have purchased diodes from snoctony on ebay. They have always been quality diodes and I have found him to be a good seller who ships fairly quickly.