光电导天线辐射阻抗特性模拟分析(英文)

针对连续太赫兹光电导天线辐射功率较低的缺点,利用有限积分方法对三种常用的光电导天线,包括偶极天线、蝶形天线和螺旋天线,进行数值模拟并分析比较其辐射阻抗特性.仿真结果表明,偶极天线的辐射阻抗与偶极长度、宽度、电极间隙以及传输线宽度有关,且在其谐振频率存在峰值阻抗,适用于特定频率的太赫兹波辐射.蝶形天线和螺旋天线在所研究的太赫兹波段具有近似稳定的辐射阻抗,广泛应用于宽带领域.对带有交叉电极的电极间隙进行计算,结果表明由交叉电极引入的附加电容降低了天线的高频阻抗.     

Generation of coherent terahertz radiation by photomixing of dual-mode lasers

We have reviewed and discussed the generation of continuous-wave terahertz radiation by the photomixing of dual-mode lasers, which includes a multi-mode laser diode (LD), a dual-mode microchip laser, a monolithic dual-mode DBR LD, and a widely tunable dual-mode external cavity LD. It is demonstrated by several experiments that the beat frequency of a dual-mode laser is more stable than the original laser modes because of the common-mode rejection effect. We also suggest a novel scheme by which the optical beat is stabilized to less than 1 kHz and its frequency can be precisely determined as well.     

Bright MM-Wave and THz Luminescence by Down-Conversion of Near-IR Amplified-Spontaneous-Emission

We report the measurement of exceptionally bright, incoherent radiation in the THz region by frequency down-conversion of amplified spontaneous emission around 775-nm wavelength. The down-conversion technique is optical mixing in an interdigital photoconductive capacitor made from ultra fast ErAs:GaAs. The brightness temperature into a single spatial mode is approximately 1.1×10⁵ K, making the new radiation at least 70 times more intense than common incandescent sources in the THz region.