THz Path Miniaturization in THz-TDS

The miniaturization of Terahertz time-domain spectroscopy (THz-TDS) systems is a critical step towards enabling their use in compact, space-constrained environments, such as planetary landers and probes. This paper explores several innovative approaches for reducing the size of the THz path while maintaining system performance. These include using silicon-based waveguides instead of traditional silicon lenses, employing antenna arrays for targeted pulse focusing, and shrinking the size of conventional silicon lenses. We also propose a new setup involving reflective mirrors and focusing lenses for sample scanning, which can fit into small borehole environments. Through a series of simulations, we evaluate the energy efficiency and pulse propagation in each of these designs, identifying the potential challenges for practical implementation in planetary exploration missions.