We designed a photo-excited broadband terahertz modulation based on electromagnetic metasurface using the tuna-ble conductivity photosensitive silicon. The metasurface consists of a special structure with hybrid photosensitive silicon and a metallic ground plane that are separated by a dielectric spacer. The resonance frequency can be varied from 1. 4 THz to 1. 0 THz when the silicon conductivity ranges from 1 S/m to 2 × 105 S/m,and the reflectivity varies from -5 dB to -38 dB. The frequency shift is 0. 3 THz,and the amplitude modulation depth reaches almost 100 ﹪ at the resonance frequency. Aband width of reflectivity less than 10 dB for the metasurface is achieved from 0 to 0. 64 THz,and the result related to the reflection phase difference of adjacent structure units. The metasurface provide a new approach to achieved wide bandwidth and range ter-ahertz modulation and have the numerous potential applications in the development of broadband communication,military ra-dar,medical image and so on.%本论文利用光敏硅的可变电导率特性，设计了一种基于光控的电磁超表面宽带太赫兹调制器.电磁超表面由金属薄膜、隔离层以及具有光敏硅的特殊结构组成.光敏硅的电导率从1 S／m变为2×105 S／m时，谐振频率从1.4 THz变到1.0 THz，其反射率从-5 dB变到-38dB，频移为0.3 THz，振幅调制深度接近100﹪，并且电磁超表面的反射率小于-10 dB的带宽从0变为0.64 THz，实现宽频带低反射主要与相邻结构单元的反射相位差有关系.该电磁超表面结构为大范围、宽频带的太赫兹调制器提供了一种新的思路和途径，将在通信、国防、成像等方面有重要的应用前景.
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