Infrared plasmonic filters integrated with an optical and terahertz multi-spectral material

Infrared plasmonic filters, consisting of subwavelength hole arrays etched into metal films, exhibit characteristics that are typically associated with the formation of surface plasmon polaritons, namely enhanced transmission and wavelength filtering of the incident light. In this article, the properties that dictate the plasmonic response of a material from the optical to the infrared regime are investigated, followed by the design, simulation, fabrication and characterisation of an infrared plasmonic filter set. Infrared plasmonic filters have also been integrated with optical plasmonic filters and a terahertz metamaterial to create a new hybrid multi-spectral material that can filter blue, green, red, near infrared, short wave infrared and two mid infrared wavelengths whilst simultaneously absorbing a single terahertz frequency. The multi-spectral material could be integrated with appropriate image sensors to create a multi-spectral camera capable of operating at optical, infrared and terahertz wavebands simultaneously.