combining 808 with green, dichro?

hi everyone,

i would like to combine a green (or if necessary other visible color) pilot-laser with a high-power IR module. module one is 808nm and will be between 10 and 30 watts. module two, in a different setup, is either 830 or 930nm (have to look it up, its years old!) and 2 watts. the modules both are fibercoupled, so pbs wont work. seems like a dichro is my only chance? i couldnt find much data on their specs in the IR.. obviously, it should pass or reflect almost all IR, even "only" 99% efficiency would mean some hundreds of mw IR bouncing around.. not to mention that several watts on a several mm² area is a high stress on any material.. ;-)
efficiency in green is uncritical, i will shine green into it until enough is making it out at the aperture ;-)

common "greenie"-ir-filters seem to do the thing, not? pass green, reflect (or absorb?) IR? they are optimized for green transmittance, not for IR reflectance though..

any ideas or hints on that? i`m surprised i didnt find any topic on that on lpf or pl..

Manuel

I would use a 45deg turning mirror that is coated for IR (you can probably find one on ebay for not to much, or thorlabs etc has them for almost resonable prices), and doesn't have a fogged back (a lot will, which makes them useless for this application). You can then shine the 532mn through it.

Short of that, http://cgi.ebay.com/Optical-Filter-...sidZp1742.m153.l1262?_trksid=p1742.m153.l1262 should work, although their graph doesn't go all of the way to 900nm

wow, that looks great! my second, "small" diode is 830nm, the graph is almost at 0% loss!
will have a look around, thank you for the hints!

manuel

I have to say that is a very nice idea, I have not tried it but will watch with interest

Regards rog8811

..dont hold your breath! ;-)
but you can be sure, however it turns out, i will keep you people here updated!

manuel

Heh heh heh...just buy something from Focalprice or the like! No dichro or combining optic needed!

-Mark