摘要
以Nd:YAG锁模激光器二倍频532 nm激光为泵浦光,用Z-扫描技术详细研究了水溶性量子点ZnS:Mn的光学非线性特性。实验结果表明,ZnS:Mn量子点对532 nm的光存在明显的双光子吸收。重点研究了在双光子吸收区ZnS:Mn量子点的非线性吸收和非线性折射,求解了不同入射光强下ZnS:Mn量子点的双光子吸收系数、双光子吸收截面、非线性折射率以及三阶非线性极化率,计算得到双光子吸收截面的最大值达10650×1050cm4.s.photon-1,平均非线性折射率为8.22×10-20m2.W-1。分析表明,ZnS:Mn量子点具有长波长的荧光发射、优良的光化学稳定性以及较小的双光子吸收截面,这些特性使其有可能成为双光子荧光分子探针。
The optical nonlinear proerties of water-soluble ZnS： Mn quantum dots have been investigated by using Z-scan technique with picosecond pulses at 532 nm wavelength. The results show that ZnS：Mn quantum dots have large two-photon absorption（TPA） at 532 nm wavdength. Based on the open-aperture Z-scan measurements, the TPA coeffidents and the corresponding TPA cross sections for five different pulse irradiances are presented. The ZnS：Mn quantum dots have average TPA cross section of 6535×10^50 cm^4· s· photon^-1 and the largest value of 10650×10^50 cm^4 · s · photon^-1. In addition, we also calculate the nonlinear refractive index and third-order nonlinear susceptibility, and the average nonlinear refractive index value is 8.22×10^-20 cm^4 · me · W^-1. All the results indicate that it is possible for ZnS：Mn quantum dots to be promising materials for fluorescent labd and imaging in biological samples.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2007年第4期443-446,共4页
Journal of Optoelectronics·Laser
基金
光电信息科学教育部重点实验室基金资助项目
关键词
ZNS:MN
水溶性量子点
双光子吸收
非线性折射率
ZnS： Mn water-soluble quantum dots
two-photon absorption（TPA）
nonlinear refractive index
