Characterization of hollow polycarbonate metal waveguides using terahertz time domain spectroscopy

In recent times, terahertz (THz) or the far-infrared region of the electromagnetic spectrum has gained critical significance due to many potential applications including medical diagnostics, nondestructive evaluation of material parameters, chemical sensing, remote sensing and security screening. However with the development of various applications, the need of guided systems for the transmission of THz radiation have posed a challenge, as a flexible waveguide could simplify the propagation and detection of THz waves in remote locations without atmospheric absorption. Different structures, such as, rigid hollow metallic waveguides, solid wires, or short lengths of solid-core transparent dielectrics such as sapphire and plastic have already been explored for THz guiding to characterize their individual loss and dispersion profile. Recently, it has been reported that copper coated flexible, hollow polycarbonate waveguide has low loss of less than 4 dB/m with single mode operation at 1.89 THz. In the present study, using a broadband THz source of photoconductive antennae, we characterize the loss and dispersion profile of hollow core polycarbonate metal waveguides in the frequency range of 0.2 to 1.2 THz.