Nanofilters for Optical Nanocircuits

TL;DR

This paper presents a theoretical and numerical framework for designing optical nanofilters, enabling complex frequency responses in nanocircuits at THz, infrared, and optical frequencies, inspired by RF circuit principles.

Contribution

It introduces a systematic design approach for optical nanofilters using nanocircuit theory, bridging RF filter design concepts with optical nanocircuit applications.

Findings

Designed basic and complex nanofilters for optical frequencies

Demonstrated similarity between optical nanofilter responses and RF filters

Provided theoretical foundation for nanofilter fabrication in optical devices

Abstract

We theoretically and numerically study the design of optical 'lumped' nanofiltering devices in the framework of our recently proposed paradigm for optical nanocircuits. In particular, we present the design of basic filtering elements, such as low-pass, band-pass, stop-band and high-pass 'lumped' nanofilters, for use in optical nanocircuits together with more complex designs, such as multi-zero or multi-pole nanofilters, to work at THz, infrared and optical frequencies. Following the nanocircuit theory, we show how it is possible to design such complex frequency responses by simple rules, similar to RF circuit design, and we compare the frequency response of these optical nanofilters with classic filters in RF circuits. These results may provide a theoretical foundation for fabricating nanofilters in optical lumped nanocircuit devices.