Investigation of THz thermal emission from electromagnetic crystals

Thermal emission at THz frequencies from an electromagnetic (EM) crystal is investigated both theoretically and experimentally. Because the photon density of states (DOS) of an EM crystal becomes redistributed, a large enhancement in the thermal emission within a desired frequency range may be possible. Band diagrams and DOS of both silicon and Tungsten woodpile structures are calculated and their thermal radiation intensity estimated. Theoretical results show that an enhancement factor of 12 around 360 GHz, compared with normal blackbody radiation, could be achieved for the silicon woodpile structures. A silicon woodpile structure was designed and fabricated. Thermal emission measurements were conducted by Fourier transform spectroscopy (FTS).