Selectively emissive refractory metal surfaces

In this letter is decribed a spectrally selective tungsten light-emitting surface, employing submicron surface texturing produced by reactive ion etching. The average emissivity of this surface throughout the visible wavelength range of 0.3–0.7 μm is greater than 0.9 compared to ∼0.4 for ordinary tungsten. At longer infrared wavelengths, however, the emissivity of the etched surface approaches that of a smooth tungsten surface. This results in enhanced efficiency in the production of visible light.