小孔径蝴蝶型光电导天线太赫兹辐射源的研究

研究了5种小孔径光电导天线的太赫兹发射特性，并且对它们所发射的太赫兹波进行了对比，为研制高效率的太赫兹波发射源提供了参考依据。利用太赫兹时域光谱技术测量了光电导天线发射的太赫兹（THz）脉冲，得到了时域发射光谱，并通过快速傅里叶变换得到相应的频域光谱。结果表明，太赫兹信号强度随偏置电压的增大而增强；随着泵浦激光功率的增大而增强并出现饱和现象。偏置电压与泵浦激光功率相同时，我们对比5种光电导天线产生的太赫兹信号，从中找到了一种发射效率较高的小孔径光电导天线，并且研究了电极形状、电极间距对光电导天线发射效率的

Study on Terahertz Source of Small-aperture Bow-tie Photoconductive Antenna

The terahertz (THz) radiation properties of five kinds of small-aperture bow-tie photoconductive antennas are studied and then compared the character of THz radiation generated by them.Meanwhile,it also provides reference to investigate and fabricate the high efficient THz radiation source.The emission spectra of the photoconductive antenna are obtained by THz time domain spectroscopy (TDS) technology.The corresponding frequency domain spectra are obtained by fast Fourier transform (FFT).The results show that when the bias voltage is enhanced,the peak value of THz radiation is increased and saturated with the increase of pump power.Under the same bias voltage and pump power,the properties of THz radiation generated by five kinds of small-aperture photoconductive antennas were compared to choose one photoconductive antennas with higher radiation property.The influence of the photoconductive shape and photoconductive gap on the THz radiation is also researched.