Infrared radiation filament and method of manufacture

The principal component of an improved IR radiation source described is a radiation filament (3) having a textured surface produced by seeded ion bombardment of a metal foil (10) which is cut to a serpentine shape and mounted in a windowed housing (1). Specific ion bombardment texturing techniques tune the surface to maximize emissions in the desired wavelength range and limit emissions outside that narrow range, particularly at longer wavelengths. A combination of filament surface texture, thickness, material, shape and power circuit feedback control produce wavelength controlled and efficient radiation at much lower power requirements than devices of the prior art.