为了提高长波量子阱红外探测器的灵敏度及探测率，采用表面等离激元效应来提高量子阱红外探测器中二维光栅的耦合效率。利用三维时域有限差分算法，分析表面等离激元作用下，长波量子阱红外探测器中二维金属薄膜光栅参数对入射光的调制作用。计算结果表明，对于8 μm的入射光，当光栅周期P=2.8 μm，孔直径D=1.4 μm，光栅层厚度L=0.04 μm时，X-Y平面内Z方向电场值最大，光栅的耦合效率最高。

In order to improve the sensitivity and detectivity of the long-wavelength quantum well infrared photodetector (QWIP) ,the surface plasmon was adopted to enhance the optical coupling efficience of two-dimensional grating . The modulation effects of the 2-D metal film grating parameters in long-wavelength QWIP on the incident light were analyzed by using the 3-D finite-difference time-domain (FDTD) algorithm based on surface plasmon. Calculation results shown that the electric field along the Z direction reaches its maximum in the X-Y plane when the grating parameters were taken as P=2.8 μm , D=1.4 μm and L=0.04 μm for 8 μm incident light.