# Building an IR illuminator



## matt304 (Mar 13, 2009)

Me and another fellow want to put together some cheap IR laser illuminators that will be decent in output for our night vision. Maybe 300-500mw IR output.

I basically would like to grab some leadlights with the right diode power, remove the crystals, then install some adjustable optics up front which can be adusted on-the-fly for beam diameter. I could cut the body shorter to get the front lens closer to the diode and still be accessible.

Can anyone recommend a lens assembly which would work for these IR illuminators? Just looking for a source to order from.

I did find a 3 pack of these leadlights pretty cheap (3 for $77) here: http://www.amazon.com/dp/B001MHBM16/?tag=cpf0b6-20

Thanks


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## comozo (Mar 13, 2009)

Edmund Optics has IR lenses. How will you adjust an invisible beam ?


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## Benson (Mar 13, 2009)

comozo said:


> Edmund Optics has IR lenses. How will you adjust an invisible beam ?



Wild guess: he'll use NVG to see it?


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## matt304 (Mar 13, 2009)

Yeah, I posted that it was an illuminator for night vision.

I'm not sure I see any small optics assemblies at the Edmund site for this specific purpose. Could you possibly give an example? Thanks


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## Benson (Mar 13, 2009)

This doesn't address your direct request, but why do you want to use a laser? Why not an IR LED? Then you could use most flashlight optics (reflectors or lenses) to focus the beam as desired.


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## matt304 (Mar 13, 2009)

Benson,

I made an IR illuminator myself using a leadlight. It has a beam which can be kept very tight, and will illuminate objects over a mile away. I have not personally seen any IR LEDs do that. The only problem with mine is that it has a multimode diode, and the beam is somewhat speckled. Anyways, the focusing lens I used was from a brass diode assembly, and I'm not quite sure where the assembly came from. It fits perfect into a leadlight body snugly. I'm just looking for cheap, single lens adjustable optics like I used here.

At the same time, I was thinking about building a more powerful illuminator in addition to these. Can single-mode 9mm 808nm or greater diodes be had of 500mw-1W, cheaply, or do they get very expensive?


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## Benson (Mar 14, 2009)

matt304 said:


> Benson,
> 
> I made an IR illuminator myself using a leadlight. It has a beam which can be kept very tight, and will illuminate objects over a mile away. I have not personally seen any IR LEDs do that. The only problem with mine is that it has a multimode diode, and the beam is somewhat speckled. Anyways, the focusing lens I used was from a brass diode assembly, and I'm not quite sure where the assembly came from. It fits perfect into a leadlight body snugly. I'm just looking for cheap, single lens adjustable optics like I used here.


Wow! Didn't realize you were after that kind of range -- a laser makes perfect sense. I was thinking of rather more close-range stuff.



> At the same time, I was thinking about building a more powerful illuminator in addition to these. Can single-mode 9mm 808nm or greater diodes be had of 500mw-1W, cheaply, or do they get very expensive?


Well, not 9mm that I've seen, but regular surface-mount high-power LED packages are readily available in the 0.5W to 3W range. There's some here, including a 3W 850nm for $7.38, premounted on a star PCB.

One option I'd consider would be taking one of these focusable LED lights, swapping out the LED+star for the 3W IR, and possibly changing the driver and/or battery pack to suit. That would get you anything from a fairly tight focus (beamshot with a white LED here) to a broad, smooth flood.


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## matt304 (Mar 14, 2009)

That's a good idea, but I'm not so sure it would compare to the collimation of a laser, which is what I am trying to achieve. I'm looking for long distance illumination.

Really, all I'm looking for is a lens assembly which will fit a leadlight body.


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## Benson (Mar 14, 2009)

My bad, I didn't catch "single-mode" there, and from what was left, somehow assumed you were asking about LEDs, not LDs -- for a higher-power, but shorter-range & wider, illuminator.

I've no significant knowledge of LD availability, nor of the sort of lenses you're after; I think I'll go back to my (flashlight) side of the forum before I confuse anything else. 

BTW, the only non-laser light-source I can think of that would readily reach the sort of range you're after: an HID spotlight behind a cold-mirror.


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## matt304 (Mar 14, 2009)

Benson,

It's OK. I kept saying IR "illuminator", when I should have been saying IR "laser".


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## comozo (Mar 15, 2009)

matt304 said:


> Me and another fellow want to put together some cheap IR laser illuminators that will be decent in output for our night vision. Maybe 300-500mw IR output.
> 
> I basically would like to grab some leadlights with the right diode power, remove the crystals, then install some adjustable optics up front which can be adusted on-the-fly for beam diameter. I could cut the body shorter to get the front lens closer to the diode and still be accessible.
> 
> ...


Ok so you want to build a IR collimator ready made to fit into a Leadlight body. Not gonna happen. The best that you can do construct your own. Or buy one of these collimators from LaserMate TC10x http://www.lasermate.com/optics.htm and attack it to the front.
Then swap out these lenses for IR ones that fit or lenses they carry that will work well for the wavelength. I think LaserMate sells this unit minus lenses
The shortest focal length negative lens Edmunds carry off the shelf is -6mm x 6mm diameter.
Edmund optics has it own forum. They will also send you a free catalog


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## scottydoesntno (Mar 23, 2009)

wrong thread


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## scottydoesntno (Mar 23, 2009)

dp


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