Eur. Phys. J. D (2012) 66: 92
https://doi.org/10.1140/epjd/e2012-20587-5

Regular Article

Build-up processes of an optical cavity enclosing an absorbent thin film: computational study by the CIP method

¹ East Tokyo Laboratory, Genesis Research Institute, Inc., 717–86 Futamata, Ichikawa, 272-0001 Chiba, Japan
² Cluster Research Laboratory, Toyota Technological Institute in East Tokyo Laboratory, Genesis Research Institute, Inc., 717–86 Futamata, Ichikawa, 272-0001 Chiba, Japan

^a Present address: Department of Chemistry, Graduate School of Sciences, Kyushu University, 812-8581 Fukuoka, Japan. e-mail: terasaki@chem.kyushu-univ.jp

Received: 11 October 2011
Received in final form: 8 February 2012
Published online: 19 April 2012

Abstract

Propagation of monochromatic light is analyzed by numerical calculations for an optical cavity enclosing a thin absorbent film. The computational study is performed by the CIP (constrained interpolation profile) method, which is shown to be able to solve temporal evolution of Maxwell’s equations even in a strongly absorbing medium. Simulations on build-up processes reveal that such a cavity exhibits transmittance even higher than the intrinsic transmissivity of the absorbent, i.e., the absorbent is virtually transparent, when the following requirements are satisfied: the film is much thinner than the wavelength, it is located at a node of a standing wave, and the cavity consists of a pair of mirrors with optimal reflectivity depending on the film thickness. Optimal conditions are discussed as well for maximizing absorption in the film.