Silicon lens-coupled bow-tie InGaAs-based broadband terahertz sensor operating at room temperature

A passive detection scheme for broadband, 10 GHz–2.52 THz, sensing at room temperature is demonstrated using a hemispherical silicon lens-coupled diode of an asymmetrically-shaped bow-tie geometrical form. The device is fabricated from an MBE-grown In0.54Ga0.46As wafer as mesas of 3 µm depth produced by wet etching. The detector exhibits voltage sensitivity about 5 V/W below 1 THz.