Chisel-edged screens to reduce loss in highly overmoded THz iris lines with finite screen thickness

Abstract

In this note we report observations on the growth trends of diffraction power loss and ohmic power loss, as functions of screen thickness, in highly overmoded THz iris-line waveguides that are constructed from thin screens. Recent theoretical developments have given a detailed field description, including eigen and transient analyses, that characterizes such waveguides under paraxial dipole-mode excitation. Informed by these analyses, we can better estimate -- and minimize -- power loss effects due to finite screen thickness in practical realizations. A geometric variation is proposed whereby we limit the growth trend in ohmic loss, even when using relatively thicker screens in practice.