Hi Don, of course Nikon used to make the SB-140 flash that had three changeable sensors, one for normal, one for UV and one for IR. This link explains
http://www.ultraviolet-photography.com/
Also spot the other link on that page for "Beyond Visible". I notice that Nikon do IR flash adapters for the SB-600 & 800, - I like your shot of the camera & rose. By the way one of these articles speaks briefly about the effect of the fresnel screen on the front of the flash and how it lessens the power of an IR flash.