Photonic Structures Based Thermal Rectification : Toward Tunable Radiative Thermal Rectifiers
Résumé
Thermal rectification can be defined as an asymmetry in the heat flux when the temperature difference between two interacting thermal reservoirs is reversed. We present here a thermal rectifier concept based on far-field radiative heat transfer. The device is composed of two opaque thermal baths 1 and 2 at temperatures T1 and T2 respectively and exchanging heat through thermal radiation. The two interacting bodies are made of spectrally selective photonic structures, Fabry−Péerot like resonant cavities in this case, with different thermooptical properties. First, we show that the mismatch between the temperature dependence of the two structures optical properties is at the origin of thermal rectification. Then, we show that the rectification ratio of a given device can be simply tuned with a few parameters such as the operating temperature and the wavelengths of the caviy resonant modes.