Otsuji Taiichi, Hanabe Mitsuhiro, Nishimura Takuya, Sano Eiichi
Opt Express. 2006 May 29;14(11):4815-25. doi: 10.1364/oe.14.004815.
A novel terahertz plasma-wave photomixer that can improve the conversion gain and terahertz radiation power is proposed and evaluated. The photomixer is based on a high-electron mobility transistor and incorporates doubly interdigitated grating strips for the gate electrodes that periodically localize the 2D plasmons in 100-nm regions with a micron-order interval. A vertical cavity structure is formed in between the top metal grating and a terahertz mirror placed at the backside. The device features electronic tuning of plasmon characteristic frequencies, providing continuously-tunable operation below 1 THz to beyond 10 THz. Frequency-dependent finite-differential time-domain analysis demonstrates that the grating-bicoupled plasmonic structure acts as a broadband terahertz photomixer and antenna and that the vertical cavity structure effectively enhances the conversion gain and radiation power.
提出并评估了一种新型太赫兹等离子体波光混频器，它能够提高转换增益和太赫兹辐射功率。该光混频器基于高电子迁移率晶体管，并在栅电极中采用了双叉指光栅条，这些光栅条以微米级间隔在100纳米区域内周期性地定位二维等离子体激元。在顶部金属光栅和位于背面的太赫兹镜之间形成了垂直腔结构。该器件具有等离子体特征频率的电子调谐功能，可在低于1太赫兹至超过10太赫兹的范围内提供连续可调操作。频率相关的有限差分时域分析表明，光栅双耦合等离子体结构可作为宽带太赫兹光混频器和天线，并且垂直腔结构有效地提高了转换增益和辐射功率。
