A terahertz generation system that emits pulsed THz radiation and incorporates a rapidly oscillating, high voltage bias across electrodes insulated from a photoconductive material. The system includes an ultrafast optical pulse source configured to generate an optical pulse having a duration between about ten picoseconds and ten femtoseconds, the pulse further having a repetition rate of about one megahertz or higher. The system further includes a photoconductor configured to receive the optical pulse from the ultrafast optical pulse source and to generate a terahertz frequency pulse, the photoconductor having insulated electrodes. The system still further includes a radio frequency generator configured to apply an electric field to the photoconductor via the insulated electrodes.