The enhanced terahertz radiation from a new photoconductive antenna (PCA) hasbeen predicted by numerical simulation. Different from the conventional PCA,the proposed PCA has electrodes with sawtooth structures on the edge, whichwill introduce stronger localized bias field than common electrode (e.g.strip-line structure). In addition, the elliptical beam of the laser source isused to illuminate the sawtooth structure of the PCA, so that the effectiveregion of the terahertz excitation is enlarged and higher laser power can beapplied before saturation effect occurs. The design of the proposed PCA ispresented, and its performance is predicated by numerical analysis based on thefull-wave finite-difference-time-domain method. The simulated result showsthat, comparing with a conventional PCA, the proposed PCA achieves $1.4$ timesenhancement of the THz radiation field(i.e. peak of the time-domain THz pulse)at the same condition. Further enhancement as high as $2$ times can be achievedwhen considering the upper limit of the power density of the incoming laserbeam.
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