title: Highly efficient light emission at lambda = 1.5 microm by a three-dimensional tungsten photonic crystal.
abstract: For what is believed to be the first time, a three-dimensional tungsten photonic crystal is demonstrated to emit light effectively at wavelength lambda = 1.5 microm. At a bias of V = 7 V, the thermal emission exhibits a full width at half-maximum of delta lambda = 0.85 microm. Within this narrow band, the emitted optical power is 4.5 W and the electrical-to-optical conversion efficiency is approximately 22% per emitting surface. This unique emission is made possible by a large, absolute bandgap in the infrared lambda and flat photonic dispersion near the band edges and in a narrow absorption band.