Large local temperature gradient induced by surface plasmon heating of periodic metal structure

Mixtures of several gas or solution having different concentration can be separated by the gradient of temperature. This is the so-called Soret effect. This phenomenon is quite important for chemical reaction and material condensation/separation. For activating large Soret effect, it would be useful to focus on the surface plasmon heating (SPH) of metal nanostructures that interact with light. In this work, a local temperate gradient was created with the aid of SPH achieved for periodic silver structures in a mesoscopic length scale fabricated by a nanosphere lithography method. Excitation of this periodic structure (by blue laser, for example) could create a localized periodic temperature gradient, as large as \textasciitilde 1,000 K/$\mu $m, as suggested from preliminary heat-transfer calculation. Experimental and theoretical results will be presented on site