摘要
Nonlinear optical absorption and nonlinear refraction were studied in ultrafine GaAs particles embedded in SiO2 thin films by use of the single-beam Z-scan technique at room temperature. An enhanced third-order nonlinear absorption coefficient and nonlinear refractive index were measured to be about 10-1 cm/W and 10-3 esu, respectively. The saturated optical absorption and two-photon absorption, under a 104 W/cm2 irradiation intensity, were observed and discussed. Results show that the enhanced nonlinear effect mainly depends on the quantum confinement effect. Under the strong quantum confinement condition, the Coulomb interaction effect is negligible with respect to the quantum confinement effect, and the feature of nonlinear optical effect of the GaAs particles behaves as a two-level system.
Nonlinear optical absorption and nonlinear refraction were studied in ultrafine GaAs particles embedded in SiO2 thin films by use of the single-beam Z-scan technique at room temperature. An enhanced third-order nonlinear absorption coefficient and nonlinear refractive index were measured to be about 10-1 cm/W and 10-3 esu, respectively. The saturated optical absorption and two-photon absorption, under a 104 W/cm2 irradiation intensity, were observed and discussed. Results show that the enhanced nonlinear effect mainly depends on the quantum confinement effect. Under the strong quantum confinement condition, the Coulomb interaction effect is negligible with respect to the quantum confinement effect, and the feature of nonlinear optical effect of the GaAs particles behaves as a two-level system.
基金
National Natural Science Foundation of China
Centre of Structure Analysis,University of Science and Technology of China.
