Information theoretical analysis of hierarchical nano-optical systems in the subwavelength regime

Optical near-field interactions exhibit a hierarchical response, which is one of the most unique attributes of light-matter interactions occurring locally on the nanometer scale. It allows hierarchical nano-optical systems that break through the integration restrictions posed by the diffraction limit of conventional propagating light and offers multiple hierarchical functionalities at different physical scales in the subwavelength regime. Here we demonstrate an information theoretical approach to such nano-optical systems while assessing their electromagnetic and logical aspects via angular-spectrum analysis. Mutual information at each level of the hierarchy reveals quantitatively the relation between the physical effects associated with the hierarchy in the optical near-fields, as well as possible environmental disturbances affecting the system locally or globally, and the system's capabilities for information processing and communication.