Fabrication of Tungsten Photonic Crystals for High Efficacy Incandescent Light Emitters

Tungsten "woodpile" 3D photonic crystals in the visible wavelength scale can potentially suppress light emission in the infrared range and, when used as black-body filaments, enhance black body emission in the visible range. Such a device would act as an ideal light bulb providing high luminous efficacy and perfect color rendering index, Here five hundred nanometer period tungsten photonic crystals are fabricated using a novel holographic lithography and wafer bonding method to realize a layer by layer stacked woodpile structures. Reflection characterization of two layer structures shows evidence of enhanced reflection and suggests a bandgap starting at 900 nm.