Study of self-focusing effect induced by femtosecond photodisruption on model substances

We have studied the possible nonlinear effects on tissue and model substance with emphasis on self-focusing effect. The nature of this effect and its biological consequences are discussed. We have studied how the self-focusing action changes with applied laser power and its effect on various depths of the biological materials. Critical power for biological material is calculated, and the peak power required for surgical purposes is found to be greater than the critical power. Furthermore, we discuss other possible effects that self-focusing might have on refractive surgery.