Study of far field temporal characteristics of terahertz radiation generated by large-aperture photoconductive antennas with finite thickness

The far field temporal characteristics of terahertz radiation caused by biased large-aperture photoconductive antennas with finite thickness was analyzed using current surge model which not only include effects of finite lifetime and transient mobility, but also effects of optical time lag and absorption attenuation in photoconductor material. The dependence of the waveforms of the radiated field on optical fluence, carrier relaxation time, carrier lifetime and material thickness are discussed in detail. The contrast is made between terahertz temporal profiles including antennas thickness and excluding thickness.