Conflicts of interest/Competing interests (include appropriate disclosures)There are no conflicts to declare.Availability of data and material (data transparency) Supporting information available.
Code availability (software application or custom code) Not applicableAuthors' contributions (optional: please review the submission guidelines from the journal whether statements are mandatory) Graham Dawson, Xiaorong Cheng and Anthony Centeno contributed to the conception and design of the study. FDTD calculations were performed by Anthony Centeno. Experiments were performed by Wentian Niu, Yulia Pilyugina and Ruochen Liu.