Measuring Radiative Heat Transfer Enhancement at the Nanoscale
Résumé
It has been predicted theoretically that for distances smaller than the peak wavelength of the blackbody spectrum, radiative heat transfer can be increased by the contribution of evanescent waves [1]. These effects have already been observed but a quantitative comparison is still missing. We measure the heat flux between a sphere and a plate as a function of the sphere-plate distance. We find a good agreement between the experimental and theoretical results . Particularly, the distance dependence is well reproduced by the theory in a large range of gap widths: 50nm-2μm.