Tantalum Selenide Micro-Wafer Terahertz Emitter

Abstract

Terahertz waves possess distinct characteristics, including such as transience, coherence, low energy, penetration, and fingerprint spectroscopy, which render them well-suited for a diverse range of applications in security inspection, nondestructive testing, and environmental detection. However, the efficiency of terahertz wave generation remains constrained by the terahertz source. To address this limitation and minimize losses in the generation process, the selection of band-gap-free semi-metallic materials, as terahertz radiation sources, is of utmost importance. We successfully fabricate TaSe₂ micro-wafer measuring 1×0.5 μm. By employing optical pumping at a wavelength of 1040 nm and a pulse duration of 150 fs, we achieve a terahertz output of nearly 0.005 μW. This output surpasses the terahertz generation efficiency of GaP crystals by approximately 20% under the same power density. Furthermore, we conduct investigations into the impact of incidence and optical polarization on terahertz wave generation. TaSe₂ exhibits suitability for high-efficiency, micro–nano-scale terahertz wave generation applications, such as on-chip terahertz systems and micro–nano terahertz sources.