Measurement of coherent transition radiation from electron beam using large-apeture photoconductive antenna

Generation of femtosecond electron bunches has been investigated for a light source based on electron bunches and improvement of time resolution in time-resolved measurements. In this study, temporal electric fields from electron bunches using a photoconductive antenna (PCA) with radial microstructures were measured. Radially polarized terahertz (THz) pulses from femtosecond electron bunches were generated by coherent transition radiation (CTR). Electric-field-induced current from the PCA depending on THz electric field was measured.