Efficient infrared emission from periodically patterned thin metal films on a Si photonic crystal

We have fabricated a periodic array of holes with diameters of a few microns on thin metal films on a Si substrate by using lithographic techniques, and demonstrate that the structures show extraordinary transmission in the infrared spectrum. Our structures become efficient narrow-band infrared thermal emitters when the hole pattern is transferred to the Si substrate by dry etching using the metal as a mask. The influence of the geometrical parameters, like the hole depth and diameter, on the emission spectra was considered in order to optimize the optical properties.