I noticed that some trail cameras seem to utilise black IR, as the normal IR gives off a red light, so I thought maybe, you could buy Black IR illuminator off the shelf for use on a NV rifle scope?
ScoutGuard Black IR Long Range Trail CameraThe ScoutGuard SG560K-8M is able to capture high resolution pictures and video with a very high picture quality and clarity, long battery life, fast trigger time, true black 940nm LEDs and a built in colour LCD display. 32GB memory card support and VGA quality video.What also sets the Scoutguard SG560K-8M apart from the competition is the new patented PIR technology that constantly delivers up to 25 meter range and 55 degrees.Uniform night vision is also achieved with a diffractive glass cover providing fantastic night vision results and what's more because is black IR, its totally invisible.