基于石墨烯冷阴极的太赫兹微型谐振腔倍频器研究

现有的太赫兹频段半导体固态倍频器发展迅速，但仍存在功率低，增益低的不足之处。本项目利用石墨烯冷阴极优异的场发射特性及其场发射电流电压关系具有的非线性效应，提出一种新型的可工作在太赫兹频段的冷阴极谐振腔倍频器。我们利用重入式谐振腔诱导太赫兹频段电磁波驱动石墨烯冷阴极进行场发射，产生具备太赫兹频率的电子束。利用场发射的非线性效应，可分解得具备二次/三次谐波分量的电子束。最后通过高压偏置加速电子束以提高谐波能量，并通过输出腔滤波输出倍频太赫兹信号，实现高功率的太赫兹波的倍频器。我们进一步研究利用微加工技术制备微米尺度的冷阴极谐振腔倍频器，以实现在硅基底上制成微纳真空电子器件，满足太赫兹器件对尺寸小型化的需求，同时也拓展冷阴极真空微纳电子器件在太赫兹波段集成片上系统的应用领域。

The performance of terahertz semiconductor solid state multiplier is in a strong development. However, its harmonic power and gain are still no good enough. In this program, we propose a novel terahertz cold cathode cavity multiplier, by utilizing the nonlinear relation in field emission of graphene cold cathode. The terahertz signal is induced into the cavity and drive on field emission of graphene cold cathode. Then the field emission electron beam with a terahertz frequency is accelerated by an external bias. At last the harmonic component of the electron beam which due to the field emission nonlinear relation is convert to a double frequency terahertz wave in the output cavity. We also investigate the microfabrication of cold cathode cavity multiplier in micrometer scale aiming at miniaturization and assemble the vacuum electronic device on chip and satisfying the requirement of terahertz device.