Congratulations to final year PGRs James Capers and Dean Patient, whose paper ‘Inverse design in the complex plane: Manipulating quasi-normal modes’ has been recently accepted by Physical Review A.
James explains the importance of this paper’s findings:
To design materials for use in solar panels, gas sensors and thermal emitters it is necessary to control the spectral response of the material. Currently, this design is often done by manually tuning parameters of the resonator which can be numerically expensive and time consuming. In this work we have utilised the quasi-normal mode framework, commonly applied to photonic resonators, to present two efficient semi-analytic techniques to place the resonances of a structure at particular complex frequencies. Our approach is numerically efficient and allows for the control of the wavelength of the resonance and its linewidth simultaneously.
Please see below for abstract:
Abstract:
Utilising the fact that the frequency response of a material can be decomposed into the quasi–normal modes supported by the system, we present two methods to directly manipulate the complex frequencies of quasi–normal modes in the complex plane. We first consider an `eigen–permittivity’ approach that allows one to find how to shift the permittivity of the structure everywhere in order to place a single quasi–normal mode at a desired complex frequency. Secondly, we then use perturbation theory for quasi–normal modes to iteratively change the structure until a given selection of quasi–normal modes occur at desired complex frequencies.