太赫兹信号源的固态电路实现-回顾与展望

The Solid-State Realization of THz Signal Source——A Review and Projection

频率为0.3 3 THz(太赫兹)信号源的固态电路实现是一个极具挑战、但又有重要应用(在生物医疗、成像与通信领域)的课题。该文以非受限于载流子渡越时间(non transit-time limited)手段产生该频段THz信号源为主要讨论内容,回顾了其物理机理,特征及技术上尚待改进的问题等。所涉及到的THz源实现方法包括:1)采用III-V族器件的基波振荡器;2)利用硅基CMOS振荡电路的高次谐波合成;3)高电子迁移率场效应晶体管(HEMT)沟道中等离子体波不稳定性;4)量子级联激光器(QCL:Quantum Cascade Laser)。

The solid-state-circuit realization of terahertz signal sources with frequency range of 300 GHz （0.3 THz） to 3 THz （1 THz=1012 Hz） is a big challenge, yet has great applications, including biomedical, imaging, and communications.In this article, the THz signal generation, mainly by means of non-transit time limited mechanisms , is discussed , and the physical origins , characteristics , and engineering problems to be solved are reviewed .The methods for generating THz sources covered in this article include：1 ） fundamental oscillators using III-V devices;2） the signal combination of high-order harmonics in silicon CMOS oscillators;3 ） exploration of the plasma-wave instability in channel electrons in HEMTs （ high electron-mobility transistors）;4） quantum cascade lasers （QCLs）.