Thermally controllable reduction of absorption and extinction of a dielectric sphere by an InSb coating

The absorption and extinction efficiencies of a sphere covered by InSb coating and illuminated by an incident plane wave in the terahertz gap were computed. Numerical results shows that these efficiencies, for some core materials and in some spectral regimes, can be reduced by adjusting the temperature. This, reduction of absorption and extinction by the InSb coating is not possible for air and metallic spheres, but it is possible for dielectric spheres. Furthermore, the InSb coating is more effective in absorption reduction for more dissipative dielectric materials, whereas it is more effective in extinction reduction for less dissipative dielectric materials.