利用飞秒脉冲通过Z扫描技术和泵浦-探测技术研究了CdS0.2Se0.8纳米晶掺杂的硼酸盐玻璃滤波片RG665的非线性吸收特性。研究结果表明在800 nm波长 130 fs脉冲激光作用下, RG665滤波片表现较强的非线性吸收特性。通过理论分析拟合实验结果证明RG665滤波片在800 nm下的非线性吸收包含双光子吸收及双光子吸收诱导的激发态吸收两部分, 得到双光子吸收系数为0.05 cm/GW, 激发态吸收截面为σe=3×10-23 m2, 以及导带中低能态电子和导带底电子的寿命分别为13 ps和210 ps。研究结果表明CdS0.2Se0.8纳米晶体掺杂的玻璃是一种很好的非线性光学材料。

The nonlinear absorption properties of borate glass doped with CdS0.2Se0.8 nanocrystal (RG665) were investigated using Z-scan and pump-probe techniques with femtosecond pulses. It was found that RG665 showed strong nonlinear absorption under 130 fs laser pulses at 800 nm wavelength. By theoretically analyzing the experimental results, the nonlinear absorption of RG665 included two parts: two-photon absorption and the excited state absorption induced by two-photon absorption at 800 nm wavelength. The two-photon absorption coefficient was obtained to be about 0.05 cm/GW, the excited state absorption cross section was σe=3×10-23 m2, and the electron lifetime on the low energy state and bottom in conduction band was 13 ps and 210 ps respectively. The research results certify that the borate glass doped with CdS0.2Se0.8 nanocrystal is a good kind of nonlinear optical material.