太赫兹量子阱光电探测器光栅耦合的模拟与优化

Simulation and optimization of grating optical coupling of terahertz quantum well photodetector

光栅耦合是量子阱光电探测器探测正入射电磁辐射的常用耦合方法,本文采用模式展开法研究了一维金属光栅太赫兹量子阱光电探测器中的电磁场分布,并给出了器件有源区中的平均光强.研究结果表明,若一维光栅的周期与太赫兹波在器件材料中的波长相当,并且根据器件结构选取合理的光栅占空比,可使器件中的平均光场最强,光栅的光耦合效率最高,从而提高器件的响应率.

The grating optical coupling method is commonly used for detecting the normal incident light with a quantum well photodetector.In this paper,the distribution of electromagnetic field in one-dimensional metal grating terahertz quantum well photodetectors is studied with modal method,and the average light intensity in the active region is obtained.The result shows that,the light intensity in the device can be optimized when the period of the grating is comparable with the wavelength of the terahertz wave in the sample and a proper filling factor is chosen according to the device structure,which will improve the responsivity of the device.