Device and method for bowtie photoconductive antenna for terahertz wave detection

A bowtie photoconductive antenna configured to detect terahertz waves, comprising:

• a substrate having a top side and a bottom side;
• a Gallium Arsenide (GaAs) layer deposited on said top side of said substrate;
• a plurality of metal electrodes deposited directly on said Gallium Arsenide layer;
• and
• an extended hemispherical lens attached to said bottom side of said substrate, wherein said plurality of metal electrodes comprises a bowtie-shaped dipole with an excitation gap at the center for optical pulse irradiation, and wherein said extended hemispherical lens further comprises an extension layer and a hemispherical layer separated by an extended line, wherein the position of said extended line within said extended hemispherical lens is selected so that a beam of light coming from outside of said extended hemispherical lens is collimated to said excitation gap.