A multi-spectral image is a collection of several images taken at different wavebands. An image that combines data from several spectrally specific cameras can convey more information than images of a single wavelength. In order to record separate spectral bands commonly a range of different cameras or filters must be used. Therefore, the integration of different wavebands on a single chip is highly disirable for multi-spectral imaging.
David Cumming (University of Glasgow) and co-workers have demonstrated a new type of multi-spectral material that hybridises optical plasmonic filters with a terahertz metamaterial absorber to combine multiple functionalities as well as multi-spectral capabilities into a single material. They fabricated a synthetic multi-spectral material that combines fifteen color plasmonic filters, a single infrared plasmonic filter and a frequency selective terahertz metamaterial absorber. Their device shows that the presence of plasmonic filter arrays have negligible impact on the THz absorption associated with the metamaterial. By using a single material with multiple engineered optical properties over the same surface area this study opens up the possibility of creating high resolution multi-spectral imagers.
