Design and analysis of optical sensors composed of large arrays of nanowires using the surface impedance generating operator (SIGO) method

Abstract

Abstract The design and analysis of large arrays of nanoscale scattering elements using existing computational tools is particularly difficult. Such difficulty mainly arises from large number of unknowns and the way existing CAD tools handle the analysis of complex nanostructures. In this work, a simple, reliable and fast analytical tool is introduced based on the surface impedance generating operator method, which not only reduces the number of unknowns through surface discretisation of the scatterers but can also be implemented in a parallel process, reducing simulation time. Circular and linear arrays of nanowires are designed using the proposed method to have a directive pattern and to be deployed in a rake‐shaped optical probe head. The far‐field scattering patterns of the arrays are investigated. In addition, the effects of array configuration as well as the number of elements and their properties on the directivity and beamwidth of the scattering patterns are also evaluated. Finally, high‐resolution directive scanning probes made of a circular array of 31 gold nanowires and a linear array of 15 elements are designed at 800 nm with less than 3° beamwidth.

Keywords

• probes
• optical sensors
• nanowires
• gold
• nanophotonics
• nanosensors