Abstract: A method of radiative cooling of optoelectronic devices using a hyperbolic metamaterial TIM layer below the heat generating optoelectronics is disclosed. Optoelectronic devices are optimized for high radiative heat conductance due to broad hyperbolic frequency band in the Long-Wavelength Infrared (LWIR) range with an efficient electromagnetic black hole thermal interface between the metamaterial TIM layer and a metallic heat sink. A modified Stefan-Boltzmann law in the hyperbolic metamaterial layer enables domination of the radiative heat transfer in the TIM layer. The broadband divergence of the photonic density of states in hyperbolic metamaterials leads to an increase in radiative heat transfer, beyond the limit set by the Stefan-Boltzmann law. The resulting radiative thermal hyper-conductivity approach or even exceed heat conductivity via electrons and phonons in regular solids.

Abstract: Disclosed herein are exemplary embodiments of materials and structures that have a negative refractive index. For example, one exemplary embodiment is a waveguide structure comprising a first waveguide border element having a first substantially planar surface, and a second waveguide border element spaced apart from the first waveguide border element and having a second substantially planar surface. This exemplary embodiment further comprises a core material positioned between the first substantially planar surface and the second substantially planar surface. The core material has a positive in-plane dielectric constant and a negative perpendicular-to-plane dielectric constant. Furthermore, the first waveguide border element, the second waveguide border element, and the core material form a waveguide exhibiting a negative index of refraction for electromagnetic radiation in a frequency range.