Photophysical Properties Of Lead Sulfide And Zinc Sulfide Quantum Dots

In recent years, with the development of photoelectric science, the nonlinear optics became a can't divided part of the photoelectric technology, in the meantime, the nonlinear optical formed a series of interdisciplinary science with other research areas. Semiconductor quantum dots exhibit a very broad applications in field of optical switches, optical limiters and optical communications because of their unique quantum confinement effect, surface effect,strong nonlinear optical effect and so on. Therefore, the photophysical properties research of semiconductor quantum dots has become the forefront of research in the 21 st century, and it also has profound effect on the progress of the future science and technology.In this paper, the photophysical properties of the water-soluble PbS, ZnS, Ag2 S quantum dots, especially the nonlinear optical properties were studied.This paper introduces the development and research status of nonlinear optical and semiconductor quantum dots material, describes the experimental devices and theoretical analysis of the traditional Z-scan and Top-hat disk Z-scan, and show the preparation and characterization of three kinds of quantum dots in detail.Based on Top-hat beam Z-scan, we bulit experimental light path. The nonlinear absorption and nonlinear refraction characteristecs of three kinds of quantum dots were studied under nanosecond, picosecond, femtosecond pulse width, calculate the nonlinear absorption index, the nonlinear refractive index and the third-order nonlinear polarizability. Meanwhile compared the nonlinear optical properties of three kinds of quantum dots under the femtosecond pulse width, analyzed the different laser wavelength and pulse width on the influence of the nonlinear optical properties. Our research provide practical theory basis for further explore the nonlinear optical effect of semiconductor quantum dots.