Dependence of terahertz photoconductive switch performance on metal contact geometry

Abstract

This study investigates the emission and spectral characteristics of photoconductive THz switches employing coplanar stripline contact geometries fabricated on a GaAs substrate. The experimental results reveal how the power outputs as well as the spectral shape are significantly influenced by the strip width dimension. Utilizing the Drude–Lorentz conductivity model, photocarrier dynamics were analyzed through an RLC circuit framework, offering insights into how the contact design influences the spectral response. Our findings suggest that matching the photocurrent impedance to that of the metallic contacts is critical to improving the efficiency of these devices.