论文标题
使用等离子体波Terahertz场效应晶体管的超短脉冲检测和响应时间分析
Ultrashort Pulse Detection and Response Time Analysis Using Plasma-wave Terahertz Field Effect Transistors
论文作者
论文摘要
我们报告了用飞秒和皮秒脉冲喂养的等离激元terahertz场效应晶体管（Terafets）的响应特征。在恒定输入功率条件下，将脉冲宽度（TPW）从10-15 s变为10-10 s，发现了两种独特的脉冲检测模式。在短脉冲模式下（tpw << l/s，l是门控通道的长度，s是等离子体速度），源对电压响应是急剧的脉冲振荡衰减，此前是在l/s的延迟时间之前的延迟时间。血浆波像带有相对狭窄的波封装的浅水波一样沿着通道传播。在长脉冲模式（tpw> l/s）中，响应曲线具有两个振荡衰减过程，并且等离子体波的传播是类似于用一侧固定的振荡杆的类似物。长脉冲模式下的最终响应时间明显高于在短脉冲条件下。长脉冲模式下的检测条件接近步进响应条件，响应时间非常符合阶跃函数响应的分析理论。模拟的波形与测量的脉冲响应很好。我们的结果表明，脉冲响应的测量值可以从脉冲响应数据（包括有效的质量，运动学粘度和动量松弛时间）中提取物料参数。
We report on the response characteristics of plasmonic terahertz field-effect transistors (TeraFETs) fed with femtosecond and picosecond pulses. Varying the pulse width (tpw) from 10-15 s to 10-10 s under a constant input power condition revealed two distinctive pulse detection modes. In the short pulse mode (tpw << L/s, where L is the gated channel length, s is the plasma velocity), the source-to-drain voltage response is a sharp pulse oscillatory decay preceded by a delay time on the order of L/s. The plasma wave travels along the channel like the shallow water wave with a relatively narrow wave package. In the long pulse mode (tpw > L/s), the response profile has two oscillatory decay processes and the propagation of plasma wave is analogues to oscillating rod with one side fixed. The ultimate response time at the long pulse mode is significantly higher than that under the short pulse conditions. The detection conditions under the long pulse mode are close to the step response condition, and the response time conforms well to the analytical theory for the step function response. The simulated waveform agrees well with the measured pulse response. Our results show that the measurements of the pulse response enable the material parameter extraction from the pulse response data (including the effective mass, kinematic viscosity and momentum relaxation time).
