Printed terahertz metasurfaces for multispectral imaging by thermo-conversion

In this work, we investigate the fabrication and the application of ultra-thin terahertz metasurfaces as thermal converters for indirect terahertz imaging. The microstructures fabricated by an ultrasonically driven printing process (Microplotter) are used to improve the THz to IR conversion efficiency and tune the spectral or polarisation selectivity. The resulting conversion membranes show optical and thermal responses which are consistent with numerical simulations establishing reliable rules to design such membrane at various wavelengths. This work paves the way for a low-cost solution of multispectral terahertz imaging with a standard infrared camera.