Arsenide-based terahertz materials and devices for 800 and 1550 nm excitations

Abstract

Photoconductors based on III-V semiconductor compounds, and suitable for 800 and 1550 nm excitations, were grown using the low temperature growth technique in a Molecular Beam Epitaxy (MBE) system. Photoconductive antennas were fabricated and tested in a time-domain spectroscopy (TDS) system. The photoconductors were synthesised to absorb light at the wavelengths of 800 nm or 1.55 μm. The photoconductive antennas were composed of aperture and dipole structures. A combination of the unique material characteristics, such as femtosecond carrier lifetime, high dark resistivity and high mobility, and the geometry of the antenna structures resulted in the development of fully operational THz devices at both excitation wavelengths.