The mechanical interaction between an electromagnetic field and a nanoscopic thin film near electronic resonance is theoretically studied by calculation of Maxwell's stress tensor. As a result of numerical demonstrations for both propagating and evanescent incident waves, the following effects that are specific to this condition have been clarified: (1) The force exerted on a nanoscopic thin film is greatly enhanced near the resonance frequency to the same order of magnitude as for a film with macroscopic thickness. (2) The peak position of the gradient force in its spectrum is highly sensitive to the change in nanoscopic thickness that is due to the polaritonic effect. (3) In a total-reflection region a large enhancement of the repulsive force between the two thin films occurs when the films act as an optical cavity.
© 2002 Optical Society of America
Takuya Iida and Hajime Ishihara, "Study of the mechanical interaction between an electromagnetic field and a nanoscopic thin film near electronic resonance," Opt. Lett. 27, 754-756 (2002)