Thank for your advise! Yes the baffles are aligned perpendiclar to the detector, preventing signal from reaching the detector except in one plane.
My concern was the baffles may have significant contribution to reflectance of marginally (fractions of a degreee) off-axis signals but as you say...
That should do well to start. Basically have a beam directivity descriminator (fins) that will prevent spurious and off-axis emission detection. I would like to apply absorbing material to the fins to assure minimal reflection into the receiver.
Cheers
Eric
Attempting to find a material, paint etc. best suited to absorb Infrared around the 940nm wavelegnth. Source is from commonly available IR LED used for all types of transmiters.
Cheers
Eric