Calculations for Tera-Hertz (THz) Radiation Sources

We explore possibilities for THz sources from 0.3 - 30 THz. While still inaccessible, this broad gap is even wider for advanced acceleration schemes extending from X or, at most, W band RF at the low end up to CO2lasers. While physical implementations of these approaches are quite different, both are proving difficult to develop so yet lower frequency, superconducting RF is preferred. Similarly, the validity of modelling techniques varies greatly over this range but generally mandates coupling Maxwell’s equations to the appropriate device transport physics for which there are many options. Here we study radiation from undulatory-shaped transmission lines using finite-difference, time-domain (FDTD) simulations. Also, we present Monte-Carlo techniques for pulse generation. Examples of THz sources demonstrating constructive interference are shown with the goal of optimizing on-chip radiators.