Alignment of Terahertz Transmission Setups with Free-Space Laser Photoconductive Switches

A systematic procedure for ensuring perfect alignment of Photoconductive Antennas (PCA) in transmittance measure setups with free-space laser PCA gap feeding and mechanical adjust of silicon substrate lenses is presented. The method is especially suited to research studies for characterization of PCA geometries. An example of measured spatio-temporal beam pattern is shown.