针对可见光通信对硅基光电探测器高响应度的要求，本文利用亚波长金属光栅的异常光学透射现象，提出一种增强与硅基CMOS工艺兼容的金属-半导体-金属光电探测器吸收的方法。采用时域有限差分法，详细分析了光栅周期、光栅高度和狭缝宽度对探测器吸收性能的影响，证明了类法布里-珀罗共振和表面等离子体激元是吸收增强的物理起源。对于波长615 nm的红光通信而言，探测器金属光栅的最佳周期、最佳高度和最佳狭缝宽度分别为580，91，360 nm。与没有亚波长金属光栅结构的探测器相比，本文设计的探测器吸收系数提高了32%。本文研究的MSM探测器结构与CMOS工艺完全兼容，有望在可见光通信芯片中得到实际应用。

To meet the requirement of high responsivity of silicon-based photodetector in visible light communication (VLC), a novel silicon-based metal-semiconductor-metal photodetector utilizing the abnormal optical transmission of subwavelength metal grating was proposed. The effects of grating height, grating period and slit width on the absorptive performance of the photodetector were analyzed in detail by using the method of finite difference time domain. The simulation results indicate that the absorption enhancement was improved by the Fabry-Perot resonance and the surface plasmon polariton. For the VLC system with a wavelength of 615 nm, the optimum period, the optimum height and the optimum slit width of the metal grating are 580, 91, 360 nm, respectively. The absorption efficiency of the designed detector was 32% higher than that of the detector without metal grating. Since the proposed photodetector is based on standard CMOS process, it has potential application in the visible light communication.