摘要
采用飞秒激光激励光导开关能够产生脉宽皮秒甚至亚皮秒级的太赫兹脉冲,近年来,这项技术成为校准宽带示波器上升时间的有效手段。以低温生长砷化镓(LT-GaAs)为光导开关的基底,在飞秒激光激励下产生太赫兹脉冲,经共面波导传输,通过微波探针耦合为1.85mm同轴输出,然后利用带宽70GHz的取样示波器对其半幅度宽度进行测量。实验获得太赫兹脉冲的半幅度宽度(FWHM)约为7.4ps。
Picosecond or subpicosecond electrical pulses can be generated by using femtosecond laser excited photoconductive switches. And this technique is an effective method to calibrate the rise time of the broadband oscilloscopes recently. In this paper, low temperature grown GaAs(LT-GaAs) is used as the substrate of the photoconductive switch which is excited by the femtosecond laser. After propagating along a coplanar waveguide, the generated terahel:tZ pulses are transferred to a 1. 85 mm coaxial cable through a microwave probe. The pulse width is measured in a 70 GHz sampling oscilloscope. The FWHM value is about 7.4 ps in the experiment.
出处
《光学与光电技术》
2012年第6期62-65,共4页
Optics & Optoelectronic Technology