Tyndall scattering in colloidal solution of quantum dots under the action of laser pulses

The high-intensity nanosecond laser pulses scattering in strongly absorbing colloidal solutions of CdSe/ZnS quantum dots has been investigated. Different types of nonlinear Tyndall scattering mechanism was revealed as a function of excitation radiation intensity. At the low laser pulses intensity (up to 15 MW/cm(2)) saturation of the basic exciton transition in strongly absorbing colloidal solution of CdSe/ZnS quantum dots was observed. In this case of average laser pulses intensity (15-200 MW/cm(2)) the dominant scattering mechanism is scattering on dipoles induced by the electric field and scattering on density fluctuations of the dispersed medium around bleached quantum dots. At the higher intensity (200-4000 MW/cm(2)), the predominant scattering mechanism is the scattering on bubbles of gas formed around local heating centers - colloidal quantum dots.