Z扫描法研究nc-Si/SiN_x多量子阱材料非线性光学特性

采用射频磁控反应溅射技术与热退火处理制备了nc-Si/SiN_x多量子阱材料.对样品进行了小角度XRD、Raman光谱、吸收光谱测试,研究了其结构和光学性质.采用皮秒脉冲激光单光束Z-扫描技术研究了样品在非共振吸收区的三阶非线性光学特性.实验结果表明,其非线性折射率为负值,非线性吸收属于双光子吸收.由实验数据计算得材料三阶非线性极化率为7.50×10~(-8)esu,该值比体硅材料的三阶非线性极化率大4个数量级.对材料光学非线性产生的机理进行了探讨,认为材料的非线性极化率的增加来源于材料量子限制效应增强.

Abstract：

The nc-Si/SiN_x multi-quantum well (MQW)was prepared by RF magnetron sputtering technique and thermal annealing. The sample was tested by low-angle XRD, Raman spectrometry and absorption spectrometry, and its structure and optical properties were studyed. Nonlinear optical properties of nc-Si/SiN_x MQW were probed by a Z-Scan Technique. The experimental results show that the nonlinear refractive index of the sample is a negative value and the nonlinear absorption is two-photon absorption. After calculating, it is obtained that X~((3)) of the sample is 7.50 10~(-8)esu, the value of nc-Si/SiN_x MQW is 4 orders of magnitude higher than that of bulk Silicon. The nonlinear mechanism of the material was discussed. The enhancement of nonlinear refractive index is mainly attributed to the enhancement of quantum confinement.

Study on Non-linear Optical Properties of nc-Si/SiN_x MQW with Z-scan Method

The nc-Si/SiN_x multi-quantum well (MQW)was prepared by RF magnetron sputtering technique and thermal annealing. The sample was tested by low-angle XRD, Raman spectrometry and absorption spectrometry, and its structure and optical properties were studyed. Nonlinear optical properties of nc-Si/SiN_x MQW were probed by a Z-Scan Technique. The experimental results show that the nonlinear refractive index of the sample is a negative value and the nonlinear absorption is two-photon absorption. After calculating, it is obtained that X~((3)) of the sample is 7.50 10~(-8)esu, the value of nc-Si/SiN_x MQW is 4 orders of magnitude higher than that of bulk Silicon. The nonlinear mechanism of the material was discussed. The enhancement of nonlinear refractive index is mainly attributed to the enhancement of quantum confinement.