Thermal antenna behavior for thin-film structures

I show that under proper conditions, thin-film structures behave as thermal sources that are able to emit radiation in well-defined directions over abroad spectral band for both p- and s-polarization states of light. This effect results from the quantization of modes inside the structure as in a Fabry-Perot resonator. A theoretical demonstration of this effect is given by using the matrix transfer method. This result is similar to the most efficient reported results with gratings but with use of a completely different physical principle (C) 2004 Optical Society of America.