| Semiconductor nanocrystals embedded in organic or inorganic matrix are used to synthesize nonlinear optical materials with large nonlinear refractive index and quick response time, which can be widely applied in nonlinear optical equipment, like optical switch, optical operation, optical wave-guide and optical absorber, et al. So they are researched as a hotspot by lots of countries. Basic theoretics are systemic expatiate in this paper, and several kinds of methods for synthesis of semiconductive nanomaterials are presented simultaneously. We briefly introduced the history, research progress, application of nonlinear optical materials in the recent year, especially the quantum dot effect of semiconductor quantum dot doped glass.Na2O-B2O3-SiO2 glasses doped with semiconductor PbS and CdS quantum dots were fabricated via a sol-gel route in this paper. The microstructure of PbS and CdS quantum dots doped glass and the existence of quantum dots and their nonlinear optical effect are investigated. The results indicate that PbS quantum dots have a mean diameter of 3.5 nm, and the nonlinear refractive indexγand the nonlinear absorption coefficientβare 7.05×10-10cm/GW and -2.03×10-14 cm2/GW, respectively. The absorption edge of CdS quantum dots exhibited a blue shift comparing with bulk CdS crystal and theγis -9.13×10-15cm2/GW. Both of the two kinds of quantum dots are self-defocusing matrices with nonlinear saturable absorption properties, which have a potential application in the nonlinear optical devices. |
