Omnidirectional Thz Mirror On A One-Dimensiona Porous Silicon Thermocrystal

We have designed a thermocrystal that reflects phononic thermal radiation. In the THz range, heat is kinetic energy carried predominantly by phononic vibrations. These mechanical vibrations have wavelengths that produces interferences within the internal interfaces of a phononic crystal. We determined conditions to obtain gaps simultaneously for longitudinal and transverse waves in a porous silicon multilayer. We propose a one-dimensional crystal with an omnidirectional mirror that reflects all phononic vibrations in the THz.