Optical Mode Characterization Using a VNA Phase and Amplitude Measurement Scheme at 104 GHz

We have developed a modal framework [1], which uses the notion of optical modes, i.e. an unique set of individually coherent orthogonal field distributions, to propagate an incident electric field through an optical system. The framework relies on a transmission matrix and Singular Value Decomposition (SVD), to obtained the mode characteristics: their transmission efficiencies and spatial forms over the input and output surface of the optical system. Here, we present a VNA phase and amplitude measurement scheme used for determining the transmission matrix, and we compare the obtained mode characteristics to our model for a pair of limiting slits at 104 GHz, which show good agreement.