Degree Name

Doctor of Philosophy


School of Mathematics and Applied Statistics


Optical solitary waves are supported in various nonlinear optical media. The mechanism for the formation of a solitary wave is a balance between nonlinear effects (which change the refractive index), and the dispersion or diffraction of the beam. In thermal media the nonlinearity arises due to the temperature dependent refractive index of the material. The optical beam heats the material and causes an increase in temperature, which changes the refractive index. Heat flux via the cell boundaries can also heat the medium, representing a different mechanism for changing the refractive index. The amplitude, position and stability of the solitary wave may all be changed by altering the boundary temperatures and other parameters. One dimensional solitary waves are stable for all parameter choices. As the medium is nonlocal the temperature response of the material extends far beyond the waist of the optical beam, which can stabilise two dimensional solitary waves for some parameter choices.