中文摘要：

为修复因加载过高外置偏压而被击穿的太赫兹光电导天线的发射晶体，采用离子注入法对光电导间隙区域进行了2MeV He^＋离子注入处理。经过10^16 ions／cm^2 He^＋离子处理后，光电导天线的电阻由约800Ω变为60MΩ，基本恢复到了击穿前的水平。通过对比辐照前后太赫兹发射源在空气气氛中的时域谱和频域谱，发现离子辐照后太赫兹信号强度有了十分明显的增强，时域光谱峰值信号电流由辐照前的2nA增加到了辐照后的8nA，峰值功率增幅超过了一个量级，且发现处理后光电导天线的频谱相对于辐照前有了明显的展宽。

英文摘要：

The irradiation of solids by energetic particles may cause extensive displacement cascades and point defects （vacancies and interstitials）, and can be widely used for material modification. In order to repair an electrical breakdown photoconductive antenna （PCA）, we irradiated the （100）-oriented, low-temperature （LT） grown GaAs substrate with 10^16/cm^2 of 2 MeV helium ions. After being implanted, electric resistance of the PCA has increased from 800 Ω to 60 MΩ. The irradiated PCA exhibits improvements in the output power in comparison with the electrical breakdown PCA and its signal intensity has increased from 2 nA to 8 nA. Accordingly, its output power has become more than one order of magnitude higher than that before irradiation. The frequency range of PCA has obviously improvement.