微纳复合结构增强硅基太赫兹调制器性能

研究了由微米金字塔阵列和纳米级氧化铝(Al2O3)薄膜构成的微纳复合结构对硅基光控太赫兹调制器调制性能的增强效应和机制。实验表明，相对于半导体硅片，硅表面的微米金字塔阵列能够显著减少激光反射率，提高对激光的利用率，且能增加太赫兹波的调控面积。更重要的是，金字塔阵列上沉积的纳米级厚度Al2O3薄膜还能进一步降低激光反射率，并能明显提升太赫兹波的调制效果，在95.5 mW/mm2的激光功率密度下，其调制深度可达91.2%。该光控太赫兹调制器在低激光功率下拥有高调制深度，在太赫兹成像和通信领域都有巨大的应用潜力。

Performance of micro-nano composite structure enhanced silicon-based terahertz modulator

The enhancement effect and mechanism of the micro-nano composite structure composed of micro-pyramid array and nano-scale alumina(Al2O3) film on the modulation performance of silicon-based optically controlled terahertz modulators is studied. Experiments show that the micro pyramid array on the silicon surface can significantly reduce laser reflectivity compared with semiconductor silicon wafers, improve laser utilization, and increase the area of terahertz control. More importantly, the nano-thickness Al2O3 film deposited on the pyramid array can further reduce the laser reflectivity and significantly improve the modulation effect of the terahertz wave. Under the laser power density of 95.5 mW/mm2, its modulation depth can reach up to 91.2%. The optically controlled terahertz modulator has high modulation depth at low laser power, and shows a huge application potential in the field of terahertz imaging and communication.