Theoretical and experimental studies of metallic grids absorption: Application to the design of a bolometer

International audienceWe present a theoretical model of metallic absorbers for electromagnetic waves. This model allows the design of any kind of structured absorber metallic films and dielectrics. The absorption theory of metallic structures was studied with aim of a room temperature bolometer design. To validate the theoretical concept, grids of size much larger than the wavelength were built and measured. Transmission, reflection and absorption results obtained at 0.3 THz are in good agreement with the model. Grids of size smaller than the wavelength were built and measured at RF frequencies. Results show the tremendous influence of grid size over wavelength in term of equivalent resistivity and absorption